$151+ Cheap flights from St. Louis (STL) to Ontario
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 11/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YYZ
Nov 9 — Nov 161
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Ontario 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 St. Louis to OntarioExplore the most affordable flight options available from St. Louis to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 10, 2026.
Explore the most affordable flight options available from St. Louis to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Thu 12/106:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$409
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Thu 12/106:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$414
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/96:34 pm -
2 stops26h 18m
Thu 11/126:30 am -
1 stop17h 46m
Deal found 10/9![Multiple Airlines logo]()
$424
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Mon 12/146:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$425
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Mon 12/146:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$430
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Sat 12/126:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$442
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Sat 12/126:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$446
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Wed 12/166:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$451
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Wed 12/166:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$456
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/72:47 pm -
1 stop15h 05m
Tue 12/86:20 pm -
2 stops17h 57m
Deal found 10/9![Multiple Airlines logo]()
$461
This Mytrip deal was found by Cheapflights users on 10/6. 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.
Fri 10/306:44 pm -
3 stops20h 12m
Sun 11/11:10 pm -
2 stops23h 09m
Deal found 10/6![Multiple Airlines logo]()
$500
This Mytrip deal was found by Cheapflights users on 10/8. 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.
Fri 11/66:34 pm -
2 stops20h 20m
Fri 11/134:15 pm -
3 stops27h 59m
Deal found 10/8![Multiple Airlines logo]()
$601
Best flights from St. Louis to OntarioDiscover carefully curated flight deals from St. Louis to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 10, 2026.
Discover carefully curated flight deals from St. Louis to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 10, 2026.
This American Airlines deal was found by Cheapflights users on 10/5. 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 11/67:00 am -
1 stop8h 34m
Wed 11/1112:44 pm -
1 stop9h 54m
Deal found 10/5![American Airlines logo]()
$470
This Delta deal was found by Cheapflights users on 10/9. 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.
Fri 11/61:02 pm -
1 stop9h 34m
Fri 11/136:30 am -
1 stop17h 52m
Deal found 10/9![Delta logo]()
$565
This Mytrip deal was found by Cheapflights users on 10/10. 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 12/212:02 pm -
2 stops24h 38m
Thu 12/38:30 pm -
1 stop18h 17m
Deal found 10/10![Multiple Airlines logo]()
$599
This United Airlines deal was found by Cheapflights users on 10/7. 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.
Sun 12/66:10 am -
1 stop6h 01m
Sat 12/123:10 pm -
1 stop8h 05m
Deal found 10/7![United Airlines logo]()
$719
This Air Canada deal was found by Cheapflights users on 10/6. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/268:30 am -
1 stop7h 12m
Wed 12/97:40 pm -
1 stop4h 19m
Deal found 10/6![Air Canada logo]()
$892
This Delta deal was found by Cheapflights users on 10/10. 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.
Tue 11/107:00 am -
1 stop9h 54m
Tue 11/1710:14 am -
2 stops11h 15m
Deal found 10/10![Delta logo]()
$593
This Mytrip deal was found by Cheapflights users on 10/8. 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.
Fri 11/66:34 pm -
3 stops22h 54m
Fri 11/134:15 pm -
3 stops27h 59m
Deal found 10/8![Multiple Airlines logo]()
$606
This Delta deal was found by Cheapflights users on 10/6. 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.
Wed 11/187:00 am -
1 stop9h 54m
Mon 12/145:10 pm -
1 stop16h 42m
Deal found 10/6![Delta logo]()
$598
This Mytrip deal was found by Cheapflights users on 10/8. 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 11/14:26 pm -
2 stops26h 29m
Thu 11/54:35 pm -
2 stops17h 19m
Deal found 10/8![Multiple Airlines logo]()
$641
This United Airlines deal was found by Cheapflights users on 10/7. 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 10/286:09 am -
1 stop6h 02m
Sat 10/316:15 am -
1 stop6h 57m
Deal found 10/7![United Airlines logo]()
$719
This Delta deal was found by Cheapflights users on 10/6. 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.
Tue 11/175:00 pm -
1 stop15h 12m
Tue 12/156:50 pm -
1 stop15h 02m
Deal found 10/6![Delta logo]()
$598
This United Airlines deal was found by Cheapflights users on 10/8. 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 11/225:00 am -
2 stops13h 27m
Sun 11/296:15 am -
1 stop6h 55m
Deal found 10/8![United Airlines logo]()
$729
This Delta deal was found by Cheapflights users on 10/6. 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.
Tue 11/1710:00 am -
1 stop12h 41m
Sun 12/135:10 pm -
1 stop16h 42m
Deal found 10/6![Delta logo]()
$613
This Mytrip deal was found by Cheapflights users on 10/8. 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 11/54:26 pm -
3 stops21h 34m
Mon 11/97:35 am -
2 stops11h 07m
Deal found 10/8![Multiple Airlines logo]()
$702
This United Airlines deal was found by Cheapflights users on 10/9. 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.
Mon 12/71:18 pm -
1 stop6h 58m
Thu 12/109:45 am -
2 stops10h 41m
Deal found 10/9![United Airlines logo]()
$729
This Air Canada deal was found by Cheapflights users on 10/6. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2710:53 am -
1 stop4h 49m
Tue 11/312:05 pm -
1 stop5h 54m
Deal found 10/6![Air Canada logo]()
$892
This United Airlines deal was found by Cheapflights users on 10/6. 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.
Wed 11/258:30 am -
1 stop4h 39m
Sun 11/296:15 am -
1 stop6h 55m
Deal found 10/6![United Airlines logo]()
$730
This Delta deal was found by Cheapflights users on 10/5. 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 11/196:40 am -
2 stops10h 14m
Sat 11/2112:15 pm -
2 stops12h 07m
Deal found 10/5![Delta logo]()
$680
This Mytrip deal was found by Cheapflights users on 10/7. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:35 pm -
2 stops17h 20m
Thu 10/225:15 pm -
3 stops24h 43m
Deal found 10/7![Multiple Airlines logo]()
$768
This United Airlines deal was found by Cheapflights users on 10/9. 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.
Fri 10/306:50 pm -
1 stop23h 20m
Mon 11/28:35 am -
1 stop14h 05m
Deal found 10/9![United Airlines logo]()
$731
This Mytrip deal was found by Cheapflights users on 10/9. 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.
Thu 11/1911:29 am -
3 stops28h 55m
Sun 11/228:40 am -
3 stops27h 23m
Deal found 10/9![Multiple Airlines logo]()
$772
This Delta deal was found by Cheapflights users on 10/6. 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.
Sat 11/1411:34 am -
1 stop10h 37m
Sat 12/126:20 am -
1 stop5h 40m
Deal found 10/6![Delta logo]()
$711
This United Airlines deal was found by Cheapflights users on 10/6. 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.
Tue 11/108:00 am -
1 stop9h 57m
Thu 11/1212:05 pm -
1 stop10h 35m
Deal found 10/6![United Airlines logo]()
$757
This KAYAK deal was found by Cheapflights users on 10/9. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/263:15 pm -
1 stop5h 42m
Sat 11/282:20 pm -
1 stop7h 09m
Deal found 10/9![Delta logo]()
$718
This Booking.com deal was found by Cheapflights users on 10/9. 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.
Sun 11/14:26 pm -
2 stops16h 13m
Wed 11/47:35 am -
2 stops11h 05m
Deal found 10/9![Multiple Airlines logo]()
$805
This United Airlines deal was found by Cheapflights users on 10/8. 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 10/248:00 am -
1 stop8h 16m
Sun 11/16:15 am -
1 stop10h 28m
Deal found 10/8![United Airlines logo]()
$774
This United deal was found by Cheapflights users on 10/6. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/178:00 am -
1 stop9h 57m
Sun 12/1312:05 pm -
1 stop6h 00m
Deal found 10/6![Multiple Airlines logo]()
$858
This United deal was found by Cheapflights users on 10/9. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/105:25 am -
1 stop10h 17m
Fri 12/1112:05 pm -
1 stop7h 11m
Deal found 10/9![Multiple Airlines logo]()
$861
This United Airlines deal was found by Cheapflights users on 10/9. 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 10/271:00 pm -
1 stop4h 57m
Tue 11/312:05 pm -
1 stop5h 54m
Deal found 10/9![United Airlines logo]()
$967
Last-minute flights from St. Louis to OntarioDiscover last-minute flight deals from St. Louis to Ontario. Data last updated October 10, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Ontario. Data last updated October 10, 2026 and is based on user searches.
This Mytrip deal was found by Cheapflights users on 10/6. 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.
Fri 10/306:44 pm -
3 stops20h 12m
Sun 11/11:10 pm -
2 stops23h 09m
Deal found 10/6![Multiple Airlines logo]()
$500
This American Airlines deal was found by Cheapflights users on 10/5. 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 11/67:00 am -
1 stop8h 34m
Wed 11/1112:44 pm -
1 stop9h 54m
Deal found 10/5![American Airlines logo]()
$470
This Mytrip deal was found by Cheapflights users on 10/8. 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.
Fri 11/66:34 pm -
2 stops20h 20m
Fri 11/134:15 pm -
3 stops27h 59m
Deal found 10/8![Multiple Airlines logo]()
$601
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/96:34 pm -
2 stops26h 18m
Thu 11/126:30 am -
1 stop17h 46m
Deal found 10/9![Multiple Airlines logo]()
$424
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Thu 12/106:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$409
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Mon 12/146:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$425
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Sat 12/126:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$442
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/166:34 pm -
2 stops23h 43m
Wed 12/166:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$451
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Thu 12/106:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$414
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Mon 12/146:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$430
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Sat 12/126:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$446
This Kiwi.com deal was found by Cheapflights users on 10/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/186:34 pm -
2 stops23h 43m
Wed 12/166:30 am -
1 stop18h 42m
Deal found 10/6![Multiple Airlines logo]()
$456
One-way flights from St. Louis to OntarioSearch for one-way flight options from St. Louis to Ontario. Find affordable one-way fares based on user searches. Data last updated October 10, 2026.
Search for one-way flight options from St. Louis to Ontario. Find affordable one-way fares based on user searches. Data last updated October 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/96:34 pm -
2 stops41h 16m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Multiple Airlines logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/96:34 pm -
2 stops26h 18m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Multiple Airlines logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 10/7. 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 12/912:02 pm -
2 stops23h 48m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$187
This Kiwi.com deal was found by Cheapflights users on 10/7. 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 12/912:02 pm -
2 stops26h 18m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$194
This Kiwi.com deal was found by Cheapflights users on 10/7. 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.
Thu 12/109:50 am -
2 stops7h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 10/7. 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 12/119:50 am -
2 stops7h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$203
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/62:00 pm -
2 stops27h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Multiple Airlines logo]()
$205
This Kiwi.com deal was found by Cheapflights users on 10/7. 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 11/46:44 pm -
2 stops19h 36m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$206
This Kiwi.com deal was found by Cheapflights users on 10/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/282:00 pm -
2 stops27h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![Multiple Airlines logo]()
$206
This Kiwi.com deal was found by Cheapflights users on 10/7. 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.
Thu 11/512:14 pm -
2 stops34h 33m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Multiple Airlines logo]()
$213
This Kiwi.com deal was found by Cheapflights users on 10/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/232:00 pm -
2 stops27h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Multiple Airlines logo]()
$213
This American Airlines deal was found by Cheapflights users on 10/8. 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.
Tue 11/37:00 am -
1 stop8h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![American Airlines logo]()
$217
Find flight deals from St. Louis to Ontario
Keep the following information in mind while searching for St. Louis to Ontario flight deals. Data was last updated October 10, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $409 (Kiwi.com) |
One-way from | $151 (Kiwi.com) |
Popular in | August |
Cheapest in | January |
Average price | $559 |
Good round-trip deal | $569 or less |
Good one-way deal | $419 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis 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 7,457,451 searches. Data last updated October 10, 2026.
Use the filters below to find and compare flights from St. Louis to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Wed 12/9
12:02 pm-12:50 pm
2 stops23h 48m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$187
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 10/28
7:03 am-4:47 pm
1 stop8h 44m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$217
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Mon 11/9
5:00 pm-9:12 am
1 stop15h 12m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$234
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Sat 11/7
8:00 am-6:11 pm
1 stop9h 11m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$234
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Thu 12/10
6:13 pm-7:55 pm
3 stops24h 42m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$239
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 10/28
6:44 pm-3:20 pm
2 stops19h 36m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$246
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Mon 11/9
6:34 pm-9:58 pm
3 stops26h 24m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$248
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Tue 11/3
6:47 am-6:09 pm
2 stops10h 22m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$266
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Sun 11/22
6:05 pm-5:24 pm
3 stops46h 19m
Ottawa
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$281
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Tue 11/3
2:00 pm-3:20 pm
3 stops48h 20m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$287
Showing 1-10 of 52 resultsSorted by cheapest first
Best time to book a flight from St. Louis to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from St. Louis with our price prediction graph.
STL-YTZ
STL-YYZ
STL-YOW
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 St. Louis to Ontario
STL-CAON
STL-YTZ
STL-YYZ
STL-YOW
What is the cheapest month to book a flight from St. Louis to Region of Ontario?
Currently, March is the cheapest month in which you can book a flight from St. Louis to Region of Ontario (average of $425). Flying from St. Louis to Region of Ontario in January is currently the most expensive (average of $710). 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 STL to ON?
Find hourly flight availability from St. Louis 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 October 10, 2026.
When flying from St. Louis to Region of Ontario, 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 St. Louis to Region of Ontario
Explore weekly flight availability from St. Louis to Ontario. 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 October 10, 2026.
The most flights from STL to CAON are scheduled on a Monday (4 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (4 on average).
How much does it cost to fly round-trip from St. Louis to Region of Ontario?
Airfare is below average for this route at the moment.
St. Louis to Region of Ontario flights typically cost between $574 and $748 in November.The cheapest round-trip price found within the last 5 days was $409 on Multiple Airlines (Nov 16-Dec 10).
How far ahead should I book a flight from St. Louis to Region of Ontario?
To ensure you get the cheapest price possible for a flight from St. Louis to Region of Ontario, you should look to book at least 87 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
Reviews of airlines servicing Ontario
Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated October 10, 2026.
Get a feel of what it's like to fly with Delta,United Airlines, andAir Canada from St. Louis to Ontario by reading reviews from past customers. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
7.8
Overall
7.8
Entertainment
7.8
Crew
8.5
Food
7.2
Boarding
8.1
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Overall
7.8
Entertainment
7.8
Crew
8.5
Food
7.2
Boarding
8.1
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Overall
7.8
Entertainment
7.8
Crew
8.5
Food
7.2
Boarding
8.1
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Overall
7.8
Entertainment
7.8
Crew
8.5
Food
7.2
Boarding
8.1
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Overall
7.8
Entertainment
7.8
Crew
8.5
Food
7.2
Boarding
8.1
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Related info for your journey
Find useful and relevant information for your journey from St. Louis 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 St. Louis to Ontario
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Complete your trip
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Find flights from St. Louis to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.
St. Louis and Ontario flights
Browse other St. Louis and Ontario flight options. Last updated on October 10, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 4 airlines flying from St. Louis to Ontario
Discover the top 4 airlines that operate flights from St. Louis 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 7,457,451 searches. Data last updated October 10, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$139 | Average$548 | FlexibilityNo cancel fee | On-time67% | |
| Cheapest$203 | Average$631 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$246 | Average$623 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$270 | Average$544 | FlexibilityNo cancel fee | On-time71% |