$116+ Cheap flights from Ontario (ONT) to Chicago (CHI)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — CHI
Oct 12 — Oct 191
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to Chicago with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Ontario to Chicago are usually found in January or September, booked 85 days in advance, depart on a Saturday or Wednesday and return on a Thursday
Cheap flight deals from Ontario to Chicago
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Cheapest flights from Ontario to ChicagoExplore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 12, 2026.
Explore the most affordable flight options available from Ontario to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 12, 2026.
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/3011:45 am -
1 stop10h 38m
Tue 10/66:30 am -
1 stop6h 00m
Deal found 9/10![Frontier logo]()
$197
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/268:35 pm -
1 stop6h 41m
Wed 10/286:30 am -
1 stop6h 05m
Deal found 9/10![Frontier logo]()
$198
This Frontier deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1311:52 am -
1 stop10h 32m
Wed 10/218:30 am -
1 stop10h 18m
Deal found 9/10![Frontier logo]()
$200
This Frontier deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1711:52 am -
1 stop10h 32m
Sat 10/246:30 am -
1 stop19h 20m
Deal found 9/9![Frontier logo]()
$201
This Booking.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/316:25 am -
1 stop15h 56m
Tue 11/36:30 am -
1 stop6h 05m
Deal found 9/11![Frontier logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/28:24 pm -
1 stop7h 14m
Sun 10/48:55 pm -
1 stop16h 27m
Deal found 9/7![Frontier logo]()
$203
This CheapOair deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/198:35 pm -
1 stop6h 41m
Sat 10/246:30 am -
1 stop5h 59m
Deal found 9/8![Frontier logo]()
$204
This Mytrip deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/306:15 am -
1 stop16h 08m
Mon 10/58:55 pm -
1 stop14h 14m
Deal found 9/10![Frontier logo]()
$205
This Mytrip deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/18:24 pm -
1 stop7h 14m
Mon 10/58:55 pm -
1 stop22h 04m
Deal found 9/8![Frontier logo]()
$206
This Mytrip deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/36:15 am -
1 stop16h 08m
Wed 10/76:30 am -
1 stop19h 17m
Deal found 9/11![Frontier logo]()
$207
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1011:52 am -
1 stop10h 32m
Sat 10/178:30 am -
1 stop10h 18m
Deal found 9/10![Frontier logo]()
$209
This CheapOair deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/128:35 pm -
1 stop6h 38m
Mon 11/165:15 pm -
1 stop25h 06m
Deal found 9/10![Frontier logo]()
$210
Best flights from Ontario to ChicagoDiscover carefully curated flight deals from Ontario to Chicago that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 12, 2026.
Discover carefully curated flight deals from Ontario to Chicago that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 12, 2026.
This Southwest deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2711:55 pm -
Nonstop3h 45m
Wed 10/284:45 pm -
1 stop6h 05m
Deal found 9/8![Southwest logo]()
$245
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/312:16 pm -
1 stop8h 17m
Mon 11/96:00 am -
2 stops12h 24m
Deal found 9/9![Delta logo]()
$264
This United Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/227:00 am -
Nonstop3h 58m
Thu 11/261:30 pm -
Nonstop4h 29m
Deal found 9/8![United Airlines logo]()
$268
This Kiwi.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/145:25 pm -
1 stop24h 48m
Sun 10/189:33 pm -
1 stop11h 31m
Deal found 9/7![Multiple Airlines logo]()
$286
This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/58:45 pm -
1 stop6h 55m
Mon 11/96:05 pm -
1 stop7h 30m
Deal found 9/10![Southwest logo]()
$259
This Alaska Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/256:00 am -
1 stop9h 59m
Fri 1/19:01 am -
1 stop13h 02m
Deal found 9/11![Alaska Airlines logo]()
$561
This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1711:55 pm -
Nonstop3h 45m
Sat 10/246:35 am -
2 stops12h 25m
Deal found 9/10![Southwest logo]()
$260
This Delta deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/2311:15 pm -
2 stops11h 32m
Tue 10/2710:12 am -
2 stops14h 31m
Deal found 9/8![Delta logo]()
$294
This Southwest deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/2311:55 pm -
Nonstop3h 45m
Tue 10/274:45 pm -
1 stop6h 05m
Deal found 9/8![Southwest logo]()
$264
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/295:00 am -
1 stop6h 15m
Tue 11/34:15 pm -
Nonstop4h 32m
Deal found 9/11![United Airlines logo]()
$340
This Kiwi.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/210:32 pm -
1 stop11h 25m
Sun 12/612:47 pm -
1 stop19h 28m
Deal found 9/11![Multiple Airlines logo]()
$347
This Delta deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/31:04 pm -
1 stop6h 56m
Mon 10/57:40 pm -
1 stop6h 07m
Deal found 9/7![Delta logo]()
$317
This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/286:25 pm -
1 stop8h 35m
Sat 10/3110:30 am -
Nonstop4h 15m
Deal found 9/10![Southwest logo]()
$268
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/319:25 am -
1 stop9h 00m
Tue 11/34:15 pm -
Nonstop4h 32m
Deal found 9/11![United Airlines logo]()
$340
This Kiwi.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/185:07 pm -
1 stop16h 40m
Sun 11/2212:37 pm -
1 stop20h 30m
Deal found 9/11![Multiple Airlines logo]()
$347
This Delta deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/226:00 pm -
2 stops11h 56m
Thu 9/245:30 am -
1 stop7h 39m
Deal found 9/8![Delta logo]()
$322
This Southwest deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/128:55 pm -
1 stop6h 55m
Fri 10/167:15 pm -
1 stop6h 35m
Deal found 9/9![Southwest logo]()
$278
This United Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/197:00 am -
Nonstop3h 58m
Mon 11/234:15 pm -
Nonstop4h 32m
Deal found 9/8![United Airlines logo]()
$358
This Southwest deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1311:55 pm -
Nonstop3h 45m
Tue 11/173:55 pm -
Nonstop4h 20m
Deal found 9/11![Southwest logo]()
$297
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:15 am -
2 stops28h 07m
Thu 10/228:20 pm -
1 stop12h 44m
Deal found 9/10![Multiple Airlines logo]()
$411
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/47:00 am -
Nonstop3h 58m
Fri 11/64:15 pm -
Nonstop4h 32m
Deal found 9/11![United Airlines logo]()
$394
This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/115:25 am -
Nonstop3h 45m
Sun 2/143:50 pm -
Nonstop4h 20m
Deal found 9/10![Southwest logo]()
$298
This Southwest deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/72:00 pm -
1 stop7h 15m
Tue 10/136:05 am -
1 stop6h 40m
Deal found 9/8![Southwest logo]()
$299
This United Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2611:52 pm -
Nonstop3h 54m
Mon 1/47:59 pm -
Nonstop4h 39m
Deal found 9/10![United Airlines logo]()
$427
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/168:03 pm -
2 stops35h 37m
Thu 10/228:20 pm -
1 stop12h 44m
Deal found 9/10![Multiple Airlines logo]()
$488
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/37:00 am -
Nonstop4h 10m
Sun 10/46:07 am -
1 stop8h 11m
Deal found 9/11![United Airlines logo]()
$450
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/135:33 pm -
2 stops37h 17m
Thu 10/228:20 pm -
1 stop12h 44m
Deal found 9/10![Multiple Airlines logo]()
$510
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/51:24 pm -
1 stop6h 28m
Tue 10/68:20 pm -
Nonstop4h 29m
Deal found 9/11![United Airlines logo]()
$493
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/176:15 am -
2 stops28h 07m
Thu 10/228:20 pm -
1 stop12h 44m
Deal found 9/10![Multiple Airlines logo]()
$566
This United Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/216:30 am -
Nonstop3h 58m
Tue 2/234:05 pm -
1 stop7h 16m
Deal found 9/9![United Airlines logo]()
$508
Last-minute flights from Ontario to ChicagoDiscover last-minute flight deals from Ontario to Chicago. Data last updated September 12, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Chicago. Data last updated September 12, 2026 and is based on user searches.
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/3011:45 am -
1 stop10h 38m
Tue 10/66:30 am -
1 stop6h 00m
Deal found 9/10![Frontier logo]()
$197
This Mytrip deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/306:15 am -
1 stop16h 08m
Mon 10/58:55 pm -
1 stop14h 14m
Deal found 9/10![Frontier logo]()
$205
This Mytrip deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/18:24 pm -
1 stop7h 14m
Mon 10/58:55 pm -
1 stop22h 04m
Deal found 9/8![Frontier logo]()
$206
This Kiwi.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/28:24 pm -
1 stop7h 14m
Sun 10/48:55 pm -
1 stop16h 27m
Deal found 9/7![Frontier logo]()
$203
This Mytrip deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/36:15 am -
1 stop16h 08m
Wed 10/76:30 am -
1 stop19h 17m
Deal found 9/11![Frontier logo]()
$207
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1011:52 am -
1 stop10h 32m
Sat 10/178:30 am -
1 stop10h 18m
Deal found 9/10![Frontier logo]()
$209
This CheapOair deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/106:15 am -
1 stop16h 09m
Wed 10/148:30 am -
1 stop10h 18m
Deal found 9/9![Frontier logo]()
$210
This Frontier deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1311:52 am -
1 stop10h 32m
Sat 10/248:30 am -
1 stop10h 18m
Deal found 9/10![Frontier logo]()
$200
This Frontier deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1711:52 am -
1 stop10h 32m
Sat 10/246:30 am -
1 stop19h 20m
Deal found 9/9![Frontier logo]()
$201
This CheapOair deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/198:35 pm -
1 stop6h 41m
Sat 10/246:30 am -
1 stop5h 59m
Deal found 9/8![Frontier logo]()
$204
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/268:35 pm -
1 stop6h 41m
Wed 10/286:30 am -
1 stop6h 05m
Deal found 9/10![Frontier logo]()
$198
This Booking.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/316:25 am -
1 stop15h 56m
Tue 11/36:30 am -
1 stop6h 05m
Deal found 9/11![Frontier logo]()
$202
One-way flights from Ontario to ChicagoSearch for one-way flight options from Ontario to Chicago. Find affordable one-way fares based on user searches. Data last updated September 12, 2026.
Search for one-way flight options from Ontario to Chicago. Find affordable one-way fares based on user searches. Data last updated September 12, 2026.
This Super.com deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/18:24 pm -
1 stop7h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Frontier logo]()
$116
This Super.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/258:24 pm -
1 stop7h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$117
This Super.com deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/98:35 pm -
1 stop6h 41m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/9![Frontier logo]()
$118
This Frontier deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/88:35 pm -
1 stop6h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$119
This Southwest deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/1711:55 pm -
Nonstop3h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/9![Southwest logo]()
$120
This Booking.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/58:35 pm -
1 stop6h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Frontier logo]()
$120
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/108:32 pm -
1 stop13h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$122
This Super.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/18:03 pm -
1 stop13h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Frontier logo]()
$123
This Super.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1911:45 am -
1 stop10h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$123
This Booking.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/308:03 pm -
1 stop13h 22m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/11![Frontier logo]()
$125
This Booking.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/225:44 pm -
1 stop9h 54m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Frontier logo]()
$125
This CheapOair deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/306:15 am -
1 stop16h 08m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Frontier logo]()
$126
Find flight deals from Ontario to Chicago
Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Chicago (CHI). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 12, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $197 (Booking.com) |
One-way from | $116 (Super.com) |
Popular in | June |
Cheapest in | January |
Average price | $370 |
Good round-trip deal | $358 or less |
Good one-way deal | $183 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to Chicago that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 12, 2026.
Use the filters below to find and compare flights from Ontario to Chicago that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Sat 11/7
12:16 pm-10:33 pm
1 stop8h 17m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$130
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Tue 12/15
12:20 pm-10:55 pm
1 stop8h 35m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$130
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Wed 12/2
1:11 pm-9:56 pm
1 stop6h 45m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$130
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Mon 11/9
11:10 pm-12:51 pm
2 stops11h 41m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$135
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Tue 11/10
5:59 pm-8:50 am
2 stops12h 51m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$135
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Wed 12/9
7:00 am-9:56 pm
2 stops12h 56m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$135
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Tue 12/15
6:00 am-4:43 pm
2 stops8h 43m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$135
Quickest round-trip
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Sun 10/18
11:55 pm-5:40 am
Nonstop3h 45m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$139
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Sat 10/10
11:55 pm-5:40 am
Nonstop3h 45m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$139
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Thu 1/7
5:00 am-2:55 pm
1 stop7h 55m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$149
Showing 1-10 of 56 resultsSorted by cheapest first
Compare providers for flights from Ontario to Chicago
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Chicago in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star |
- Most accurate provider: When it comes to deals on Ontario-Chicago flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Chicago flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Chicago flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Ontario-Chicago flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-Chicago flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from Ontario to Chicago
Have a flexible travel schedule? Discover the best time to fly to Chicago from Ontario with our price prediction graph.
ONT-CHI
ONT-ORD
ONT-MDW
ONT-RFD
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from Ontario to Chicago
ONT-CHI
ONT-ORD
ONT-MDW
ONT-RFD
What is the cheapest month to book a flight from Ontario to Chicago?
Currently, October is the cheapest month in which you can book a flight from Ontario to Chicago (average of $340). Flying from Ontario to Chicago in June is currently the most expensive (average of $482). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from ONT to CHI?
Find hourly flight availability from Ontario to Chicago. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 12, 2026.
When flying from Ontario to Chicago, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Weekly flight availability from Ontario to Chicago
Explore weekly flight availability from Ontario to Chicago. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated September 12, 2026.
The most flights from ONT to CHI are scheduled on a Friday (2 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (1 on average).
How much does it cost to fly round-trip from Ontario to Chicago?
Airfare is below average for this route at the moment.
Ontario to Chicago flights typically cost between $268 and $433 in September.The cheapest round-trip price found within the last 5 days was $197 on Frontier (Sep 30-Oct 6).
How far ahead should I book a flight from Ontario to Chicago?
The best time to book flights from Ontario to Chicago is 75 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
The best insider tips for Ontario to Chicago flights
AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Ontario to Chicago trip
Our travel experts
Reviews of airlines servicing Chicago
Get insights into the airlines that provide service to Chicago. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Chicago. Reviews last updated September 12, 2026.
See what other customers who have flown with Southwest,Delta, andUnited Airlines from Ontario to Chicago have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Entertainment
7.5
Crew
8.6
Comfort
8.0
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Entertainment
7.5
Crew
8.6
Comfort
8.0
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Entertainment
7.5
Crew
8.6
Comfort
8.0
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Entertainment
7.5
Crew
8.6
Comfort
8.0
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Entertainment
7.5
Crew
8.6
Comfort
8.0
Food
7.0
Overall
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Related info for your journey
Find useful and relevant information for your journey from Ontario to Chicago. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Chicago?
Book flights to Chicago if you plan to visit one of these locationsBenton Harbor
Merrillville
Lansing
Valparaiso
Hammond
Saint Joseph
Porter
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Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
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Alternative routes for Ontario to Chicago
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Other flights to Chicago
Explore flights to Chicago departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 12, 2026.
Complete your trip
Complete your trip to Chicago by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Ontario to Chicago by cabin class
Find flights from Ontario to Chicago, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Ontario and Chicago flights
Browse other Ontario and Chicago flight options. Last updated on September 12, 2026.
Other flights from Ontario
Browse through other flights departing from Ontario. Flights are based on user searches made on Cheapflights and were last updated on September 12, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 5 airlines flying from Ontario to Chicago
Discover the top 5 airlines that operate flights from Ontario to Chicago. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 12, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$131 | Average$286 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$254 | Average$423 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$258 | Average$397 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$268 | Average$449 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$276 | Average$416 | FlexibilityNo cancel fee | On-time71% |