$109+ Cheap flights from Ontario (ONT) to Illinois
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 1/26. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — ORD
Dec 11 — Dec 181
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to Illinois 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
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Cheapest flights from Ontario to IllinoisExplore the most affordable flight options available from Ontario to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 11, 2026.
Explore the most affordable flight options available from Ontario to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 11, 2026.
This Southwest deal was found by Cheapflights users on 11/9. 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.
Wed 12/25:00 pm -
1 stop5h 15m
Sat 12/510:25 am -
Nonstop4h 20m
Deal found 11/9![Southwest logo]()
$271
This United Airlines deal was found by Cheapflights users on 11/9. 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.
Wed 12/26:40 pm -
1 stop9h 48m
Sat 12/54:15 pm -
Nonstop4h 29m
Deal found 11/9![United Airlines logo]()
$271
This Kiwi.com deal was found by Cheapflights users on 11/10. 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.
Sun 12/2010:33 pm -
1 stop29h 16m
Wed 1/61:00 pm -
2 stops21h 05m
Deal found 11/10![Frontier logo]()
$272
This Gotogate deal was found by Cheapflights users on 11/9. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/26:00 am -
1 stop8h 31m
Fri 12/48:49 pm -
1 stop12h 55m
Deal found 11/9![Multiple Airlines logo]()
$273
This CheapOair deal was found by Cheapflights users on 11/9. 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.
Wed 12/166:00 am -
1 stop16h 54m
Sun 12/207:35 am -
1 stop16h 03m
Deal found 11/9![Frontier logo]()
$274
This Mytrip deal was found by Cheapflights users on 11/8. 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.
Sun 11/158:03 pm -
1 stop11h 21m
Sat 12/127:25 am -
2 stops17h 58m
Deal found 11/8![Frontier logo]()
$275
This Mytrip deal was found by Cheapflights users on 11/8. 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.
Sat 11/146:30 am -
1 stop15h 51m
Sat 12/127:25 am -
2 stops17h 58m
Deal found 11/8![Frontier logo]()
$276
This Mytrip deal was found by Cheapflights users on 11/9. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/111:30 am -
1 stop11h 23m
Wed 12/29:13 am -
2 stops15h 07m
Deal found 11/9![Frontier logo]()
$277
This Mytrip deal was found by Cheapflights users on 11/6. 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 12/1211:30 am -
1 stop11h 24m
Wed 12/168:30 am -
2 stops16h 53m
Deal found 11/6![Frontier logo]()
$278
This Mytrip deal was found by Cheapflights users on 11/11. 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.
Thu 12/1011:00 am -
1 stop16h 01m
Tue 12/155:35 am -
2 stops18h 42m
Deal found 11/11![Frontier logo]()
$279
This Booking.com deal was found by Cheapflights users on 11/9. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/96:00 am -
1 stop16h 54m
Mon 12/1410:29 pm -
2 stops14h 16m
Deal found 11/9![Frontier logo]()
$280
This Southwest deal was found by Cheapflights users on 11/6. 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 12/192:35 pm -
1 stop7h 40m
Tue 1/55:50 am -
1 stop5h 55m
Deal found 11/6![Southwest logo]()
$281
Best flights from Ontario to IllinoisDiscover carefully curated flight deals from Ontario to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated November 11, 2026.
Discover carefully curated flight deals from Ontario to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated November 11, 2026.
This Southwest deal was found by Cheapflights users on 11/8. 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 1/196:30 am -
Nonstop3h 55m
Sat 1/234:10 pm -
1 stop5h 55m
Deal found 11/8![Southwest logo]()
$271
This United Airlines deal was found by Cheapflights users on 11/7. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/167:00 am -
Nonstop4h 11m
Thu 1/72:22 pm -
1 stop9h 53m
Deal found 11/7![United Airlines logo]()
$286
This Delta deal was found by Cheapflights users on 11/8. 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.
Wed 2/36:00 am -
2 stops10h 00m
Sat 2/69:56 am -
2 stops13h 47m
Deal found 11/8![Delta logo]()
$292
This Kiwi.com deal was found by Cheapflights users on 11/7. 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 12/2310:48 pm -
1 stop19h 35m
Mon 1/48:11 pm -
2 stops37h 54m
Deal found 11/7![Multiple Airlines logo]()
$363
This American Airlines deal was found by Cheapflights users on 11/7. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/66:00 am -
1 stop7h 48m
Sun 12/136:04 pm -
2 stops16h 41m
Deal found 11/7![American Airlines logo]()
$463
This Southwest deal was found by Cheapflights users on 11/8. 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 2/36:30 am -
Nonstop3h 55m
Sat 2/61:00 pm -
1 stop6h 50m
Deal found 11/8![Southwest logo]()
$282
This United Airlines deal was found by Cheapflights users on 11/8. 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 1/147:00 am -
Nonstop4h 00m
Sun 1/174:10 pm -
Nonstop4h 40m
Deal found 11/8![United Airlines logo]()
$309
This Delta deal was found by Cheapflights users on 11/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/41:09 pm -
1 stop8h 46m
Mon 2/812:44 pm -
2 stops13h 13m
Deal found 11/10![Delta logo]()
$336
This Southwest deal was found by Cheapflights users on 11/11. 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 1/155:20 am -
Nonstop3h 55m
Mon 1/189:30 pm -
Nonstop4h 25m
Deal found 11/11![Southwest logo]()
$319
This Delta deal was found by Cheapflights users on 11/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/47:00 am -
2 stops13h 08m
Mon 2/86:59 pm -
1 stop6h 58m
Deal found 11/10![Delta logo]()
$336
This United Airlines deal was found by Cheapflights users on 11/6. 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 11/211:29 pm -
1 stop7h 17m
Wed 11/2512:42 pm -
1 stop7h 14m
Deal found 11/6![United Airlines logo]()
$347
This Southwest deal was found by Cheapflights users on 11/10. 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.
Tue 12/85:00 pm -
1 stop5h 15m
Tue 12/154:10 pm -
1 stop6h 30m
Deal found 11/10![Southwest logo]()
$319
This Delta deal was found by Cheapflights users on 11/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/67:00 am -
2 stops12h 36m
Wed 1/271:54 pm -
2 stops12h 03m
Deal found 11/10![Delta logo]()
$365
This United Airlines deal was found by Cheapflights users on 11/9. 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.
Tue 12/2911:52 pm -
Nonstop3h 54m
Sun 1/37:52 pm -
Nonstop4h 39m
Deal found 11/9![United Airlines logo]()
$391
This American Airlines deal was found by Cheapflights users on 11/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/215:50 am -
1 stop8h 43m
Mon 1/2512:27 pm -
1 stop8h 24m
Deal found 11/11![American Airlines logo]()
$486
This Southwest deal was found by Cheapflights users on 11/6. 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 12/192:35 pm -
1 stop7h 40m
Mon 12/215:15 pm -
1 stop8h 40m
Deal found 11/6![Southwest logo]()
$384
This Delta deal was found by Cheapflights users on 11/8. 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.
Sat 11/211:15 pm -
1 stop6h 32m
Thu 11/262:00 pm -
1 stop7h 49m
Deal found 11/8![Delta logo]()
$393
This United Airlines deal was found by Cheapflights users on 11/8. 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 12/31:40 pm -
1 stop5h 22m
Sun 12/135:00 am -
2 stops9h 34m
Deal found 11/8![United Airlines logo]()
$404
This American Airlines deal was found by Cheapflights users on 11/7. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/226:00 am -
1 stop7h 37m
Thu 11/266:03 am -
2 stops13h 10m
Deal found 11/7![American Airlines logo]()
$494
This Southwest deal was found by Cheapflights users on 11/11. 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.
Sat 2/136:30 am -
2 stops8h 05m
Mon 2/155:20 am -
1 stop7h 20m
Deal found 11/11![Southwest logo]()
$394
This United Airlines deal was found by Cheapflights users on 11/6. 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.
Fri 1/225:00 am -
2 stops11h 06m
Mon 1/252:26 pm -
2 stops10h 04m
Deal found 11/6![United Airlines logo]()
$409
This Delta deal was found by Cheapflights users on 11/7. 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 11/211:15 pm -
1 stop6h 32m
Sun 11/227:30 am -
1 stop6h 50m
Deal found 11/7![Delta logo]()
$419
This United Airlines deal was found by Cheapflights users on 11/9. 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.
Sat 12/511:20 am -
2 stops9h 39m
Tue 12/158:53 am -
2 stops8h 42m
Deal found 11/9![United Airlines logo]()
$409
This American Airlines deal was found by Cheapflights users on 11/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1812:51 pm -
1 stop7h 09m
Tue 12/296:43 pm -
1 stop7h 16m
Deal found 11/10![American Airlines logo]()
$549
This Southwest deal was found by Cheapflights users on 11/10. 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 1/66:30 am -
Nonstop3h 55m
Wed 1/63:50 pm -
1 stop7h 55m
Deal found 11/10![Southwest logo]()
$417
This Delta deal was found by Cheapflights users on 11/6. 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 1/221:09 pm -
1 stop7h 40m
Tue 1/266:10 am -
1 stop7h 45m
Deal found 11/6![Delta logo]()
$434
This United Airlines deal was found by Cheapflights users on 11/8. 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.
Tue 12/15:45 am -
2 stops13h 18m
Sat 12/125:00 am -
2 stops9h 34m
Deal found 11/8![United Airlines logo]()
$421
This United Airlines deal was found by Cheapflights users on 11/8. 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.
Sat 12/1211:20 am -
1 stop8h 05m
Sun 12/207:52 pm -
Nonstop4h 39m
Deal found 11/8![United Airlines logo]()
$424
This Southwest deal was found by Cheapflights users on 11/9. 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 12/2111:55 pm -
Nonstop3h 45m
Mon 1/43:40 pm -
1 stop6h 15m
Deal found 11/9![Southwest logo]()
$467
This Delta deal was found by Cheapflights users on 11/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/211:09 pm -
1 stop7h 40m
Tue 1/266:10 am -
1 stop7h 45m
Deal found 11/11![Delta logo]()
$486
Last-minute flights from Ontario to IllinoisDiscover last-minute flight deals from Ontario to Illinois. Data last updated November 11, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Illinois. Data last updated November 11, 2026 and is based on user searches.
This Mytrip deal was found by Cheapflights users on 11/8. 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.
Sat 11/146:30 am -
1 stop15h 51m
Sat 12/127:25 am -
2 stops17h 58m
Deal found 11/8![Frontier logo]()
$276
This Mytrip deal was found by Cheapflights users on 11/8. 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.
Sun 11/158:03 pm -
1 stop11h 21m
Sat 12/127:25 am -
2 stops17h 58m
Deal found 11/8![Frontier logo]()
$275
This Mytrip deal was found by Cheapflights users on 11/9. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/111:30 am -
1 stop11h 23m
Wed 12/29:13 am -
2 stops15h 07m
Deal found 11/9![Frontier logo]()
$277
This Southwest deal was found by Cheapflights users on 11/9. 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.
Wed 12/25:00 pm -
1 stop5h 15m
Sat 12/510:25 am -
Nonstop4h 20m
Deal found 11/9![Southwest logo]()
$271
This United Airlines deal was found by Cheapflights users on 11/9. 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.
Wed 12/26:40 pm -
1 stop9h 48m
Sat 12/54:15 pm -
Nonstop4h 29m
Deal found 11/9![United Airlines logo]()
$271
This Gotogate deal was found by Cheapflights users on 11/9. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/26:00 am -
1 stop8h 31m
Fri 12/48:49 pm -
1 stop12h 55m
Deal found 11/9![Multiple Airlines logo]()
$273
This Booking.com deal was found by Cheapflights users on 11/9. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/96:00 am -
1 stop16h 54m
Mon 12/1410:29 pm -
2 stops14h 16m
Deal found 11/9![Frontier logo]()
$280
This Mytrip deal was found by Cheapflights users on 11/11. 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.
Thu 12/1011:00 am -
1 stop16h 01m
Tue 12/155:35 am -
2 stops18h 42m
Deal found 11/11![Frontier logo]()
$279
This Mytrip deal was found by Cheapflights users on 11/6. 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 12/1211:30 am -
1 stop11h 24m
Wed 12/168:30 am -
2 stops16h 53m
Deal found 11/6![Frontier logo]()
$278
This CheapOair deal was found by Cheapflights users on 11/9. 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.
Wed 12/166:00 am -
1 stop16h 54m
Sun 12/207:35 am -
1 stop16h 03m
Deal found 11/9![Frontier logo]()
$274
This Southwest deal was found by Cheapflights users on 11/6. 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 12/192:35 pm -
1 stop7h 40m
Tue 1/55:50 am -
1 stop5h 55m
Deal found 11/6![Southwest logo]()
$281
This Kiwi.com deal was found by Cheapflights users on 11/10. 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.
Sun 12/2010:33 pm -
1 stop29h 16m
Wed 1/61:00 pm -
2 stops21h 05m
Deal found 11/10![Frontier logo]()
$272
One-way flights from Ontario to IllinoisSearch for one-way flight options from Ontario to Illinois. Find affordable one-way fares based on user searches. Data last updated November 11, 2026.
Search for one-way flight options from Ontario to Illinois. Find affordable one-way fares based on user searches. Data last updated November 11, 2026.
This Super.com deal was found by Cheapflights users on 11/6. 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.
Tue 1/266:30 am -
1 stop15h 56m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Frontier logo]()
$109
This Super.com deal was found by Cheapflights users on 11/6. 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.
Tue 12/18:00 am -
1 stop18h 59m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Frontier logo]()
$111
This Super.com deal was found by Cheapflights users on 11/8. 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 12/108:44 am -
1 stop18h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![Frontier logo]()
$112
This Booking.com deal was found by Cheapflights users on 11/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/28:00 am -
1 stop18h 59m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![Frontier logo]()
$113
This CheapOair deal was found by Cheapflights users on 11/10. 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.
Mon 12/219:37 pm -
1 stop6h 12m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/10![Frontier logo]()
$116
This Frontier deal was found by Cheapflights users on 11/10. 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.
Mon 1/49:37 pm -
1 stop6h 23m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/10![Frontier logo]()
$117
This Super.com deal was found by Cheapflights users on 11/8. 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.
Sat 1/236:30 am -
1 stop15h 56m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![Frontier logo]()
$119
This Super.com deal was found by Cheapflights users on 11/9. 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 12/410:32 am -
1 stop7h 12m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$122
This Super.com deal was found by Cheapflights users on 11/6. 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.
Mon 11/168:03 pm -
1 stop13h 19m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Frontier logo]()
$128
This Southwest deal was found by Cheapflights users on 11/8. 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 2/36:30 am -
Nonstop3h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![Southwest logo]()
$131
This Mytrip deal was found by Cheapflights users on 11/9. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/158:44 am -
2 stops23h 01m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$134
This Booking.com deal was found by Cheapflights users on 11/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/811:00 am -
2 stops20h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![Frontier logo]()
$138
Find flight deals from Ontario to Illinois
Keep the following information in mind while searching for Ontario to Illinois flight deals. Data was last updated November 11, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $271 (Southwest) |
One-way from | $109 (Super.com) |
Popular in | June |
Cheapest in | April |
Average price | $363 |
Good round-trip deal | $390 or less |
Good one-way deal | $158 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to Illinois 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 November 11, 2026.
Use the filters below to find and compare flights from Ontario to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Wed 2/3
6:30 am-12:25 pm
Nonstop3h 55m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$131
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Wed 2/3
1:09 pm-11:55 pm
1 stop8h 46m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$141
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Wed 1/6
1:07 pm-10:17 pm
1 stop7h 10m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$141
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Tue 12/15
12:20 pm-10:54 pm
1 stop8h 34m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$146
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Wed 12/16
7:05 am-4:16 pm
1 stop7h 11m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$146
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Wed 2/3
7:00 am-9:36 pm
2 stops12h 36m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$146
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Tue 12/8
1:11 pm-9:56 pm
1 stop6h 45m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$146
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Thu 1/7
1:20 pm-10:08 pm
1 stop6h 48m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$156
OntarioChicago
ONT Ontario - MDW Chicago Midway
ONTMDW
Ontario
Thu 1/7
9:00 am-6:40 pm
2 stops7h 40m
Chicago Midway
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$161
OntarioChicago
ONT Ontario - ORD Chicago O'Hare Intl
ONTORD
Ontario
Fri 1/8
1:20 pm-10:08 pm
1 stop6h 48m
Chicago O'Hare Intl
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$166
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Ontario to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Ontario with our price prediction graph.
ONT-MDW
ONT-ORD
ONT-MLI
ONT-CMI
ONT-PIA
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 Illinois
ONT-USIL
ONT-MDW
ONT-ORD
ONT-MLI
ONT-CMI
What is the cheapest month to book a flight from Ontario to Illinois?
Currently, January is the cheapest month in which you can book a flight from Ontario to Illinois (average of $318). Flying from Ontario to Illinois in July is currently the most expensive (average of $481). 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 IL?
Find hourly flight availability from Ontario to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 11, 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to Illinois as you normally would.
How much does it cost to fly round-trip from Ontario to Illinois?
Airfare is below average for this route at the moment.
Ontario to Illinois flights typically cost between $336 and $499 in December.The cheapest round-trip price found within the last 5 days was $271 on United Airlines (Dec 2-Dec 5).
How far ahead should I book a flight from Ontario to Illinois?
The best time to book flights from Ontario to Illinois is 82 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.
Reviews of airlines servicing Illinois
Get insights into the airlines that provide service to Illinois. 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 Illinois. Reviews last updated November 11, 2026.
Read through reviews of airlines operating flights from Ontario to Illinois, such as Southwest,Delta, andUnited Airlines. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
8.0
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Boarding
8.1
Overall
8.0
Crew
8.6
Entertainment
7.4
Food
7.0
Comfort
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 Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for Ontario to Illinois
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Ontario to Illinois by cabin class
Find flights from Ontario to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Ontario and Illinois flights
Browse other Ontario and Illinois flight options. Last updated on November 11, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Ontario to Illinois flights
Consider these flights traveling from Ontario to Illinois.
Top 5 airlines flying from Ontario to Illinois
Discover the top 5 airlines that operate flights from Ontario to Illinois. 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 November 11, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$118 | Average$336 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$160 | Average$259 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$253 | Average$500 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$275 | Average$448 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$276 | Average$483 | FlexibilityNo cancel fee | On-time71% |