$72+ Cheap flights from Illinois to Ontario (ONT)
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 9/10. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — ONT
Sep 11 — Sep 181
Round-trip
1 adult, Economy
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Find cheap flights from Illinois to Ontario with Cheapflights
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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 Illinois to OntarioExplore the most affordable flight options available from Illinois to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 12, 2026.
Explore the most affordable flight options available from Illinois to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 12, 2026.
This Expedia deal was found by Cheapflights users on 8/12. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/101:01 pm -
1 stop7h 38m
Mon 9/148:24 pm -
1 stop7h 14m
Deal found 8/12![Frontier logo]()
$146
This Booking.com deal was found by Cheapflights users on 8/12. 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 9/146:30 am -
1 stop6h 00m
Sat 9/2610:04 am -
1 stop17h 34m
Deal found 8/12![Frontier logo]()
$152
This CheapOair deal was found by Cheapflights users on 8/12. 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 11/711:06 am -
1 stop14h 49m
Mon 11/911:19 am -
1 stop16h 16m
Deal found 8/12![Frontier logo]()
$156
This Frontier deal was found by Cheapflights users on 8/12. 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.
Thu 9/39:26 pm -
1 stop13h 12m
Sun 9/68:17 am -
1 stop10h 14m
Deal found 8/12![Frontier logo]()
$162
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/18:45 am -
1 stop12h 16m
Fri 9/49:33 am -
1 stop13h 16m
Deal found 8/11![Frontier logo]()
$162
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/111:01 pm -
1 stop7h 38m
Mon 9/148:24 pm -
1 stop7h 14m
Deal found 8/11![Frontier logo]()
$164
This Southwest deal was found by Cheapflights users on 8/11. 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.
Thu 9/102:00 pm -
Nonstop4h 10m
Mon 9/1411:55 pm -
Nonstop3h 50m
Deal found 8/11![Southwest logo]()
$165
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/108:33 pm -
Nonstop4h 26m
Sat 9/197:00 am -
Nonstop4h 10m
Deal found 8/11![United Airlines logo]()
$167
This Frontier deal was found by Cheapflights users on 8/12. 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 9/1212:17 pm -
1 stop6h 17m
Sat 9/1911:45 am -
1 stop5h 32m
Deal found 8/12![Frontier logo]()
$168
This Gotogate deal was found by Cheapflights users on 8/11. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/28:55 pm -
1 stop21h 39m
Mon 10/58:24 pm -
1 stop7h 14m
Deal found 8/11![Frontier logo]()
$168
This CheapOair deal was found by Cheapflights users on 8/12. 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 8/292:41 pm -
1 stop21h 23m
Thu 9/33:40 pm -
1 stop25h 22m
Deal found 8/12![Frontier logo]()
$172
This Trip.com deal was found by Cheapflights users on 8/11. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/248:11 pm -
1 stop21h 43m
Tue 9/87:56 pm -
1 stop26h 27m
Deal found 8/11![Frontier logo]()
$173
Best flights from Illinois to OntarioDiscover carefully curated flight deals from Illinois to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 12, 2026.
Discover carefully curated flight deals from Illinois to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 12, 2026.
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/108:33 pm -
Nonstop4h 26m
Sat 9/197:00 am -
Nonstop4h 10m
Deal found 8/11![United Airlines logo]()
$167
This Southwest deal was found by Cheapflights users on 8/11. 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 9/252:00 pm -
Nonstop4h 10m
Mon 9/2811:55 pm -
Nonstop3h 50m
Deal found 8/11![Southwest logo]()
$188
This Frontier deal was found by Cheapflights users on 8/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1010:20 am -
1 stop10h 19m
Mon 9/1411:45 am -
1 stop5h 32m
Deal found 8/7![Frontier logo]()
$252
This Delta deal was found by Cheapflights users on 8/11. 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.
Fri 10/237:35 am -
1 stop6h 46m
Sun 10/2511:15 pm -
1 stop7h 24m
Deal found 8/11![Delta logo]()
$257
This Priceline deal was found by Cheapflights users on 8/7. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/287:02 am -
1 stop8h 14m
Sun 11/12:58 pm -
1 stop5h 41m
Deal found 8/7![Multiple Airlines logo]()
$365
This American Airlines deal was found by Cheapflights users on 8/8. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/298:00 am -
1 stop6h 03m
Sat 9/52:43 pm -
1 stop6h 59m
Deal found 8/8![American Airlines logo]()
$372
This Southwest deal was found by Cheapflights users on 8/9. 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.
Fri 10/1611:55 am -
Nonstop4h 15m
Mon 10/1911:55 pm -
Nonstop3h 45m
Deal found 8/9![Southwest logo]()
$189
This Southwest deal was found by Cheapflights users on 8/10. 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.
Fri 10/233:45 pm -
2 stops8h 30m
Tue 10/2711:55 pm -
Nonstop3h 45m
Deal found 8/10![Southwest logo]()
$205
This United Airlines deal was found by Cheapflights users on 8/11. 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 10/294:15 pm -
Nonstop4h 32m
Mon 11/21:35 pm -
1 stop9h 24m
Deal found 8/11![United Airlines logo]()
$235
This Southwest deal was found by Cheapflights users on 8/11. 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 9/252:00 pm -
Nonstop4h 10m
Fri 10/211:55 pm -
Nonstop3h 45m
Deal found 8/11![Southwest logo]()
$211
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/108:33 pm -
Nonstop4h 26m
Sun 9/137:13 pm -
1 stop8h 15m
Deal found 8/11![United Airlines logo]()
$244
This Delta deal was found by Cheapflights users on 8/9. 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.
Thu 8/2012:46 pm -
1 stop7h 44m
Mon 8/2410:00 pm -
1 stop9h 59m
Deal found 8/9![Delta logo]()
$277
This Southwest deal was found by Cheapflights users on 8/12. 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 9/112:00 pm -
Nonstop4h 10m
Fri 9/1812:50 pm -
2 stops8h 35m
Deal found 8/12![Southwest logo]()
$220
This Delta deal was found by Cheapflights users on 8/7. 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 9/2611:17 am -
2 stops13h 23m
Tue 9/299:52 am -
1 stop6h 12m
Deal found 8/7![Delta logo]()
$282
This Super.com deal was found by Cheapflights users on 8/7. 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.
Thu 8/277:58 pm -
1 stop5h 52m
Sat 8/297:56 pm -
1 stop21h 17m
Deal found 8/7![Frontier logo]()
$312
This United Airlines deal was found by Cheapflights users on 8/8. 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 9/36:00 am -
1 stop8h 12m
Sun 9/61:56 pm -
1 stop7h 03m
Deal found 8/8![United Airlines logo]()
$268
This Delta deal was found by Cheapflights users on 8/11. 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.
Fri 10/97:35 am -
1 stop6h 46m
Sat 10/176:20 am -
1 stop8h 33m
Deal found 8/11![Delta logo]()
$308
This Southwest deal was found by Cheapflights users on 8/8. 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 8/269:25 am -
1 stop6h 40m
Fri 8/2811:55 pm -
Nonstop3h 50m
Deal found 8/8![Southwest logo]()
$267
This United Airlines deal was found by Cheapflights users on 8/10. 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 8/298:06 pm -
Nonstop4h 29m
Sat 9/57:00 am -
Nonstop4h 10m
Deal found 8/10![United Airlines logo]()
$298
This American Airlines deal was found by Cheapflights users on 8/8. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/98:30 am -
2 stops11h 47m
Sat 9/121:05 pm -
2 stops9h 22m
Deal found 8/8![American Airlines logo]()
$423
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/108:33 pm -
Nonstop4h 26m
Thu 9/177:13 pm -
1 stop8h 15m
Deal found 8/11![United Airlines logo]()
$298
This Southwest deal was found by Cheapflights users on 8/11. 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.
Tue 9/155:25 pm -
Nonstop4h 15m
Tue 9/2211:55 pm -
Nonstop3h 50m
Deal found 8/11![Southwest logo]()
$276
This Delta deal was found by Cheapflights users on 8/10. 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 9/26:00 am -
1 stop6h 42m
Tue 9/812:17 pm -
1 stop9h 25m
Deal found 8/10![Delta logo]()
$347
This American Airlines deal was found by Cheapflights users on 8/10. 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.
Tue 8/254:32 pm -
1 stop8h 27m
Sat 8/2912:33 pm -
1 stop7h 38m
Deal found 8/10![American Airlines logo]()
$429
This Southwest deal was found by Cheapflights users on 8/8. 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.
Thu 10/156:45 am -
1 stop8h 05m
Tue 10/202:00 pm -
1 stop7h 10m
Deal found 8/8![Southwest logo]()
$277
This United Airlines deal was found by Cheapflights users on 8/11. 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.
Tue 9/18:06 pm -
Nonstop4h 29m
Tue 9/81:56 pm -
1 stop9h 03m
Deal found 8/11![United Airlines logo]()
$321
This Delta deal was found by Cheapflights users on 8/11. 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.
Fri 9/256:55 pm -
1 stop6h 52m
Mon 9/285:15 pm -
1 stop5h 29m
Deal found 8/11![Delta logo]()
$355
This Southwest deal was found by Cheapflights users on 8/7. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/196:50 am -
1 stop7h 50m
Wed 8/261:10 pm -
1 stop8h 10m
Deal found 8/7![Southwest logo]()
$277
This American Airlines deal was found by Cheapflights users on 8/7. 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.
Sat 9/127:16 am -
1 stop6h 31m
Sat 9/1912:37 pm -
1 stop7h 09m
Deal found 8/7![American Airlines logo]()
$451
This Southwest deal was found by Cheapflights users on 8/7. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/152:40 pm -
1 stop6h 20m
Sat 9/1910:15 am -
1 stop8h 05m
Deal found 8/7![Southwest logo]()
$277
Last-minute flights from Illinois to OntarioDiscover last-minute flight deals from Illinois to Ontario. Data last updated August 12, 2026 and is based on user searches.
Discover last-minute flight deals from Illinois to Ontario. Data last updated August 12, 2026 and is based on user searches.
This Booking.com deal was found by Cheapflights users on 8/11. 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.
Sun 8/238:11 pm -
1 stop22h 11m
Thu 9/108:24 pm -
1 stop7h 14m
Deal found 8/11![Frontier logo]()
$168
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/19:10 pm -
1 stop13h 26m
Fri 9/49:33 am -
1 stop13h 16m
Deal found 8/11![Frontier logo]()
$162
This Frontier deal was found by Cheapflights users on 8/12. 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.
Thu 9/39:26 pm -
1 stop13h 12m
Sun 9/68:17 am -
1 stop10h 14m
Deal found 8/12![Frontier logo]()
$162
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/101:01 pm -
1 stop7h 38m
Sat 9/1211:45 am -
1 stop10h 38m
Deal found 8/11![Frontier logo]()
$146
This Southwest deal was found by Cheapflights users on 8/11. 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.
Thu 9/102:00 pm -
Nonstop4h 10m
Sat 9/1911:55 pm -
Nonstop3h 50m
Deal found 8/11![Southwest logo]()
$165
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/108:33 pm -
Nonstop4h 26m
Sat 9/197:00 am -
Nonstop4h 10m
Deal found 8/11![United Airlines logo]()
$167
This Southwest deal was found by Cheapflights users on 8/10. 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 9/102:00 pm -
Nonstop4h 10m
Mon 9/1411:55 pm -
Nonstop3h 50m
Deal found 8/10![Southwest logo]()
$167
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/111:01 pm -
1 stop7h 38m
Mon 9/148:24 pm -
1 stop7h 14m
Deal found 8/11![Frontier logo]()
$164
This Expedia deal was found by Cheapflights users on 8/12. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1212:17 pm -
1 stop20h 47m
Sat 9/1911:45 am -
1 stop5h 32m
Deal found 8/12![Frontier logo]()
$168
This Booking.com deal was found by Cheapflights users on 8/12. 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 9/146:30 am -
1 stop6h 00m
Sat 9/2610:04 am -
1 stop17h 34m
Deal found 8/12![Frontier logo]()
$152
This CheapOair deal was found by Cheapflights users on 8/10. 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 9/218:55 pm -
1 stop14h 14m
Sat 9/262:30 pm -
1 stop13h 08m
Deal found 8/10![Frontier logo]()
$156
This Frontier deal was found by Cheapflights users on 8/12. 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 9/266:00 am -
1 stop12h 46m
Sat 10/311:45 am -
1 stop10h 38m
Deal found 8/12![Frontier logo]()
$147
One-way flights from Illinois to OntarioSearch for one-way flight options from Illinois to Ontario. Find affordable one-way fares based on user searches. Data last updated August 12, 2026.
Search for one-way flight options from Illinois to Ontario. Find affordable one-way fares based on user searches. Data last updated August 12, 2026.
This United Airlines deal was found by Cheapflights users on 8/12. 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 9/108:33 pm -
Nonstop4h 26m
Deal found 8/12![United Airlines logo]()
$72
This Super.com deal was found by Cheapflights users on 8/11. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:54 pm -
1 stop7h 45m
Deal found 8/11![Frontier logo]()
$72
This Booking.com deal was found by Cheapflights users on 8/12. 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 10/36:30 am -
1 stop6h 00m
Deal found 8/12![Frontier logo]()
$73
This Frontier deal was found by Cheapflights users on 8/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:54 pm -
1 stop7h 45m
Deal found 8/11![Frontier logo]()
$73
This Super.com deal was found by Cheapflights users on 8/11. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/12:41 pm -
1 stop21h 23m
Deal found 8/11![Frontier logo]()
$78
This Expedia deal was found by Cheapflights users on 8/12. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/39:10 pm -
1 stop13h 28m
Deal found 8/12![Frontier logo]()
$79
This Booking.com deal was found by Cheapflights users on 8/11. 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.
Thu 9/39:26 pm -
1 stop13h 12m
Deal found 8/11![Frontier logo]()
$79
This Jetabroad deal was found by Cheapflights users on 8/12. 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 Jetabroad is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/319:26 pm -
1 stop13h 10m
Deal found 8/12![Frontier logo]()
$81
This Southwest deal was found by Cheapflights users on 8/10. 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 9/102:00 pm -
Nonstop4h 10m
Deal found 8/10![Southwest logo]()
$83
This Super.com deal was found by Cheapflights users on 8/12. 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.
Wed 9/238:10 pm -
1 stop5h 37m
Deal found 8/12![Frontier logo]()
$83
This CheapOair deal was found by Cheapflights users on 8/11. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2711:06 am -
1 stop28h 34m
Deal found 8/11![Frontier logo]()
$84
This Frontier deal was found by Cheapflights users on 8/12. 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.
Wed 9/912:17 pm -
1 stop6h 42m
Deal found 8/12![Frontier logo]()
$84
Find flight deals from Illinois to Ontario
Keep the following information in mind while searching for Illinois to Ontario flight deals. Data was last updated August 12, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $146 (Frontier) |
One-way from | $72 (United Airlines) |
Popular in | June |
Cheapest in | September |
Average price | $288 |
Good round-trip deal | $301 or less |
Good one-way deal | $206 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Illinois to Ontario 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 2,558,603 searches. Data last updated August 12, 2026.
Use the filters below to find and compare flights from Illinois to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
ChicagoOntario
ORD Chicago O'Hare Intl - ONT Ontario
ORDONT
Chicago O'Hare Intl
Thu 9/10
8:33 pm-10:59 pm
Nonstop4h 26m
Ontario
Sat 9/19
7:00 am-1:10 pm
Nonstop4h 10m
$167
ChicagoOntario
MDW Chicago Midway - ONT Ontario
MDWONT
Chicago Midway
Fri 9/25
2:00 pm-4:10 pm
Nonstop4h 10m
Ontario
Mon 9/28
11:55 pm-5:45 am
Nonstop3h 50m
$188
ChicagoOntario
MDW Chicago Midway - ONT Ontario
MDWONT
Chicago Midway
Fri 10/16
11:55 am-2:10 pm
Nonstop4h 15m
Ontario
Mon 10/19
11:55 pm-5:40 am
Nonstop3h 45m
$189
ChicagoOntario
MDW Chicago Midway - ONT Ontario
MDWONT
Chicago Midway
Fri 10/23
3:45 pm-10:15 pm
2 stops8h 30m
Ontario
Tue 10/27
11:55 pm-5:40 am
Nonstop3h 45m
$205
Quickest round-trip
ChicagoOntario
MDW Chicago Midway - ONT Ontario
MDWONT
Chicago Midway
Fri 9/25
2:00 pm-4:10 pm
Nonstop4h 10m
Ontario
Fri 10/2
11:55 pm-5:40 am
Nonstop3h 45m
$211
ChicagoOntario
MDW Chicago Midway - ONT Ontario
MDWONT
Chicago Midway
Fri 9/11
2:00 pm-4:10 pm
Nonstop4h 10m
Ontario
Fri 9/18
12:50 pm-11:25 pm
2 stops8h 35m
$220
ChicagoOntario
ORD Chicago O'Hare Intl - ONT Ontario
ORDONT
Chicago O'Hare Intl
Thu 10/29
4:15 pm-6:47 pm
Nonstop4h 32m
Ontario
Mon 11/2
1:35 pm-12:59 am
1 stop9h 24m
$235
ChicagoOntario
ORD Chicago O'Hare Intl - ONT Ontario
ORDONT
Chicago O'Hare Intl
Thu 9/10
8:33 pm-10:59 pm
Nonstop4h 26m
Ontario
Sun 9/13
7:13 pm-5:28 am
1 stop8h 15m
$244
St. LouisOntario
STL Lambert-St Louis - ONT Ontario
STLONT
Lambert-St Louis
Thu 9/10
10:20 am-6:39 pm
1 stop10h 19m
Ontario
Mon 9/14
11:45 am-7:17 pm
1 stop5h 32m
$252
ChicagoOntario
ORD Chicago O'Hare Intl - ONT Ontario
ORDONT
Chicago O'Hare Intl
Fri 10/23
7:35 am-12:21 pm
1 stop6h 46m
Ontario
Sun 10/25
11:15 pm-8:39 am
1 stop7h 24m
$257
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Illinois to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from Illinois with our price prediction graph.
ORD-ONT
MDW-ONT
STL-ONT
EVV-ONT
PIA-ONT
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 Illinois to Ontario
USIL-ONT
ORD-ONT
MDW-ONT
STL-ONT
EVV-ONT
What is the cheapest month to book a flight from Illinois to Ontario?
Currently, October is the cheapest month in which you can book a flight from Illinois to Ontario (average of $343). Flying from Illinois to Ontario in December is currently the most expensive (average of $576). 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 IL to ONT?
Find hourly flight availability from Illinois to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 12, 2026.
It’s typically best to fly out from Illinois to Ontario at noon. Doing so could potentially save you 41% on the flight price compared to flying in the morning, which is usually more expensive.
How much does it cost to fly round-trip from Illinois to Ontario?
Airfare is below average for this route at the moment.
Illinois to Ontario flights typically cost between $268 and $550 in September.The cheapest round-trip price found within the last 5 days was $146 on Frontier (Sep 10-Sep 16).
How far ahead should I book a flight from Illinois to Ontario?
The best time to book flights from Illinois to Ontario is 41 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.
Related info for your journey
Find useful and relevant information for your journey from Illinois to Ontario. 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 Illinois to Ontario
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Ontario by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Illinois to Ontario by cabin class
Find flights from Illinois to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Other flights to Ontario
Explore flights to Ontario departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on August 12, 2026.
Illinois and Ontario flights
Browse other Illinois and Ontario flight options. Last updated on August 12, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Illinois to Ontario flights
Consider these flights traveling from Illinois to Ontario.
Top 5 airlines flying from Illinois to Ontario
Discover the top 5 airlines that operate flights from Illinois to Ontario. 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 2,558,603 searches. Data last updated August 12, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$167 | Average$268 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$236 | Average$385 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$268 | Average$457 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$300 | Average$529 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$307 | Average$530 | FlexibilityNo cancel fee | On-time69% |