$117+ 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 11/2. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YYZ
Oct 29 — Nov 51
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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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from St. Louis to Ontario
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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 September 29, 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 September 29, 2026.
This Mytrip deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/116:44 pm -
2 stops19h 36m
Wed 11/1812:20 pm -
3 stops23h 59m
Deal found 9/27![Multiple Airlines logo]()
$352
This Kiwi.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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 11/265:59 pm -
1 stop18h 41m
Tue 12/112:20 pm -
2 stops23h 57m
Deal found 9/25![Multiple Airlines logo]()
$358
This Mytrip deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 10/286:44 pm -
2 stops19h 36m
Sun 11/14:20 pm -
2 stops26h 20m
Deal found 9/23![Multiple Airlines logo]()
$361
This Kiwi.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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 11/116:44 pm -
2 stops19h 36m
Sat 11/146:30 am -
1 stop17h 46m
Deal found 9/25![Multiple Airlines logo]()
$362
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 12/26:13 pm -
1 stop18h 27m
Wed 12/910:40 am -
2 stops49h 37m
Deal found 9/23![Multiple Airlines logo]()
$369
This Mytrip deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 10/286:44 pm -
2 stops19h 36m
Wed 11/47:15 am -
2 stops11h 25m
Deal found 9/24![Multiple Airlines logo]()
$382
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 10/216:35 pm -
2 stops25h 20m
Sat 10/316:30 am -
1 stop17h 46m
Deal found 9/23![Multiple Airlines logo]()
$385
This Kiwi.com deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 12/212:02 pm -
2 stops24h 38m
Sat 12/126:30 am -
1 stop18h 42m
Deal found 9/24![Multiple Airlines logo]()
$389
This Kiwi.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/236:35 pm -
2 stops25h 44m
Mon 11/96:30 am -
1 stop17h 46m
Deal found 9/26![Multiple Airlines logo]()
$393
This Kiwi.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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 11/96:44 pm -
2 stops21h 26m
Thu 11/126:30 am -
1 stop17h 46m
Deal found 9/26![Multiple Airlines logo]()
$398
This Mytrip deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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.
Mon 10/266:35 pm -
3 stops26h 23m
Wed 11/49:10 am -
3 stops27h 09m
Deal found 9/26![Multiple Airlines logo]()
$440
This Mytrip deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/116:44 pm -
2 stops20h 09m
Wed 11/187:35 am -
2 stops11h 05m
Deal found 9/27![Multiple Airlines logo]()
$461
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 September 29, 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 September 29, 2026.
This Mytrip deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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.
Mon 10/266:35 pm -
3 stops26h 23m
Wed 11/49:10 am -
3 stops27h 09m
Deal found 9/26![Multiple Airlines logo]()
$440
This Delta deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/248:00 am -
1 stop9h 11m
Fri 11/612:49 pm -
1 stop11h 32m
Deal found 9/26![Delta logo]()
$599
This United Airlines deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/118:00 am -
1 stop9h 57m
Wed 11/1812:05 pm -
1 stop10h 35m
Deal found 9/27![United Airlines logo]()
$726
This WestJet deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/256:13 am -
2 stops16h 27m
Mon 11/307:00 pm -
2 stops19h 28m
Deal found 9/28![WestJet logo]()
$947
This Mytrip deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/116:44 pm -
3 stops20h 49m
Wed 11/189:10 am -
3 stops27h 09m
Deal found 9/27![Multiple Airlines logo]()
$483
This Mytrip deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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.
Mon 11/96:44 pm -
3 stops22h 44m
Fri 11/134:15 pm -
3 stops27h 59m
Deal found 9/25![Multiple Airlines logo]()
$497
This Delta deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/246:47 am -
2 stops10h 24m
Sat 11/77:55 am -
1 stop10h 04m
Deal found 9/26![Delta logo]()
$625
This Booking.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/122:00 pm -
2 stops27h 15m
Thu 11/197:35 am -
2 stops12h 04m
Deal found 9/28![Multiple Airlines logo]()
$614
This United Airlines deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/195:36 pm -
1 stop22h 25m
Tue 10/208:55 pm -
1 stop20h 05m
Deal found 9/26![United Airlines logo]()
$758
This Delta deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/263:15 pm -
1 stop5h 42m
Wed 12/910:00 am -
2 stops11h 32m
Deal found 9/27![Delta logo]()
$747
This United Airlines deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 -
2 stops12h 18m
Sat 10/313:10 pm -
1 stop8h 44m
Deal found 9/23![United Airlines logo]()
$758
This United Airlines deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/118:30 am -
1 stop11h 46m
Wed 11/186:15 am -
1 stop6h 55m
Deal found 9/27![United Airlines logo]()
$797
This Kiwi.com deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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 12/76:00 am -
1 stop21h 00m
Wed 12/98:00 am -
1 stop17h 12m
Deal found 9/25![Multiple Airlines logo]()
$731
This United Airlines deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 10/239:04 am -
1 stop5h 42m
Fri 10/307:26 pm -
1 stop4h 58m
Deal found 9/24![United Airlines logo]()
$829
This United deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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.
Wed 10/288:00 am -
1 stop14h 52m
Sun 11/12:10 pm -
Nonstop2h 13m
Deal found 9/23![Multiple Airlines logo]()
$789
This United Airlines deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 11/88:00 am -
1 stop9h 57m
Sun 11/153:20 pm -
2 stops20h 28m
Deal found 9/24![United Airlines logo]()
$869
This United deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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.
Wed 12/96:00 am -
1 stop6h 11m
Fri 12/119:10 am -
1 stop7h 16m
Deal found 9/25![Multiple Airlines logo]()
$795
This United deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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.
Sun 10/257:30 am -
1 stop5h 39m
Sun 11/110:05 am -
1 stop6h 18m
Deal found 9/27![Multiple Airlines logo]()
$795
This United Airlines deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 11/294:05 pm -
Nonstop2h 00m
Wed 12/912:00 pm -
1 stop11h 59m
Deal found 9/23![United Airlines logo]()
$915
This United deal was found by Cheapflights users on 9/25. Clicking the “Pick Dates” 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 11/1211:29 am -
1 stop5h 20m
Mon 11/162:10 pm -
Nonstop2h 16m
Deal found 9/25![Multiple Airlines logo]()
$894
This United deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 10/271:00 pm -
1 stop4h 57m
Tue 11/312:05 pm -
1 stop5h 54m
Deal found 9/27![Multiple Airlines logo]()
$913
This United deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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 12/11:17 pm -
1 stop4h 40m
Fri 12/1112:05 pm -
1 stop6h 00m
Deal found 9/26![Multiple Airlines logo]()
$913
Last-minute flights from St. Louis to OntarioDiscover last-minute flight deals from St. Louis to Ontario. Data last updated September 29, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Ontario. Data last updated September 29, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 10/216:35 pm -
2 stops25h 20m
Sat 10/316:30 am -
1 stop17h 46m
Deal found 9/23![Multiple Airlines logo]()
$385
This Kiwi.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/236:35 pm -
2 stops25h 44m
Mon 11/96:30 am -
1 stop17h 46m
Deal found 9/26![Multiple Airlines logo]()
$393
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/236:35 pm -
2 stops25h 44m
Sat 10/316:30 am -
1 stop17h 46m
Deal found 9/23![Multiple Airlines logo]()
$421
This Mytrip deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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 10/236:35 pm -
2 stops17h 20m
Sun 11/89:10 am -
3 stops27h 09m
Deal found 9/26![Multiple Airlines logo]()
$476
This Kiwi.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/244:30 pm -
1 stop20h 10m
Tue 11/1012:20 pm -
2 stops30h 20m
Deal found 9/26![Multiple Airlines logo]()
$402
This Kiwi.com deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/247:42 pm -
2 stops43h 33m
Sat 10/316:30 am -
1 stop17h 46m
Deal found 9/23![Multiple Airlines logo]()
$410
This Kiwi.com deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/247:42 pm -
2 stops43h 33m
Mon 11/96:30 am -
1 stop17h 46m
Deal found 9/26![Multiple Airlines logo]()
$435
This Mytrip deal was found by Cheapflights users on 9/26. Clicking the “Pick Dates” 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.
Mon 10/266:35 pm -
3 stops26h 23m
Wed 11/49:10 am -
3 stops27h 09m
Deal found 9/26![Multiple Airlines logo]()
$440
This Mytrip deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 10/286:44 pm -
2 stops19h 36m
Sun 11/14:20 pm -
2 stops26h 20m
Deal found 9/23![Multiple Airlines logo]()
$361
This Mytrip deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 10/286:44 pm -
2 stops19h 36m
Wed 11/47:15 am -
2 stops11h 25m
Deal found 9/24![Multiple Airlines logo]()
$382
This Mytrip deal was found by Cheapflights users on 9/23. Clicking the “Pick Dates” 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 10/286:44 pm -
3 stops26h 14m
Sun 11/112:15 pm -
3 stops30h 25m
Deal found 9/23![Multiple Airlines logo]()
$451
This Kiwi.com deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” 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 10/294:26 pm -
1 stop20h 14m
Sun 11/11:00 pm -
2 stops25h 21m
Deal found 9/28![Multiple Airlines logo]()
$417
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 September 29, 2026.
Search for one-way flight options from St. Louis to Ontario. Find affordable one-way fares based on user searches. Data last updated September 29, 2026.
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/26:44 pm -
2 stops23h 36m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$117
This Kiwi.com deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:35 pm -
2 stops43h 20m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$139
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 11/26:44 pm -
2 stops41h 08m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$150
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/306:44 pm -
2 stops23h 36m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/306:44 pm -
2 stops42h 08m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$155
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 stops17h 08m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$161
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 12/1612:02 pm -
2 stops35h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$161
This Kiwi.com deal was found by Cheapflights users on 9/27. Clicking the “Pick Dates” 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 10/294:26 pm -
1 stop20h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/27![Multiple Airlines logo]()
$185
This Kiwi.com deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 11/96:44 pm -
2 stops18h 46m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$192
This Kiwi.com deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 10/222:00 pm -
2 stops25h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Multiple Airlines logo]()
$193
This Mytrip deal was found by Cheapflights users on 9/28. Clicking the “Pick Dates” 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 11/1212:14 pm -
3 stops26h 06m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/28![Multiple Airlines logo]()
$201
This American Airlines deal was found by Cheapflights users on 9/24. Clicking the “Pick Dates” 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 10/227:03 am -
1 stop8h 44m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![American Airlines logo]()
$210
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 September 29, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $352 (Mytrip) |
One-way from | $117 (Kiwi.com) |
Popular in | August |
Cheapest in | March |
Average price | $692 |
Good round-trip deal | $605 or less |
Good one-way deal | $410 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 September 29, 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 - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 10/14
6:35 pm-2:55 pm
2 stops43h 20m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$139
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Thu 10/22
2:00 pm-4:00 pm
2 stops25h 00m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$193
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Thu 11/12
12:14 pm-3:20 pm
3 stops26h 06m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$201
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Thu 10/22
7:03 am-4:47 pm
1 stop8h 44m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$210
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Thu 10/15
2:00 pm-4:00 pm
2 stops25h 00m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$212
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Mon 11/9
6:44 pm-12:44 am
3 stops29h 00m
Ottawa
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$218
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Thu 11/12
7:00 am-4:34 pm
1 stop8h 34m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$220
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Mon 12/21
6:05 pm-1:40 pm
1 stop18h 35m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$250
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 11/4
6:21 am-11:15 pm
1 stop15h 54m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$251
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Wed 12/16
6:13 pm-3:39 pm
1 stop20h 26m
Ottawa
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$254
Showing 1-10 of 48 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-YYZ
STL-YTZ
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-YYZ
STL-YTZ
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 $840). 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 September 29, 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 September 29, 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 $734 in November.The cheapest round-trip price found within the last 5 days was $352 on Multiple Airlines (Nov 11-Nov 18).
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 September 29, 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.
Crew
8.5
Boarding
8.1
Overall
7.8
Entertainment
7.8
Comfort
7.8
Food
7.2
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Overall
7.8
Entertainment
7.8
Comfort
7.8
Food
7.2
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Overall
7.8
Entertainment
7.8
Comfort
7.8
Food
7.2
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Overall
7.8
Entertainment
7.8
Comfort
7.8
Food
7.2
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Overall
7.8
Entertainment
7.8
Comfort
7.8
Food
7.2
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
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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St. Louis and Ontario flights
Browse other St. Louis and Ontario flight options. Last updated on September 29, 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 September 29, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$139 | Average$546 | 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% |