$201+ 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 12/10. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YYZ
Dec 10 — Dec 171
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
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.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 November 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 November 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:13 pm -
1 stop18h 27m
Thu 12/1012:20 pm -
2 stops23h 57m
Deal found 11/5![Multiple Airlines logo]()
$386
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/212:05 pm -
2 stops28h 05m
Sat 12/56:30 am -
1 stop18h 42m
Deal found 11/5![Multiple Airlines logo]()
$387
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:13 pm -
2 stops23h 02m
Thu 12/109:10 am -
2 stops27h 07m
Deal found 11/5![Multiple Airlines logo]()
$437
This Kiwi.com deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure 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 11/8![Multiple Airlines logo]()
$476
This American Airlines deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/86:02 am -
1 stop7h 40m
Wed 12/93:22 pm -
1 stop9h 40m
Deal found 11/9![American Airlines logo]()
$488
This Kiwi.com deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/96:20 pm -
1 stop18h 20m
Fri 12/116:30 am -
1 stop18h 42m
Deal found 11/7![Multiple Airlines logo]()
$501
This American Airlines deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/16:00 am -
1 stop10h 40m
Mon 12/1411:36 am -
1 stop9h 22m
Deal found 11/9![American Airlines logo]()
$503
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/412:02 pm -
3 stops35h 07m
Fri 12/113:15 pm -
3 stops20h 42m
Deal found 11/5![Multiple Airlines logo]()
$537
This Kiwi.com deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/912:02 pm -
2 stops35h 07m
Wed 12/168:00 am -
1 stop17h 12m
Deal found 11/9![Multiple Airlines logo]()
$548
This Mytrip deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/57:54 pm -
3 stops22h 57m
Mon 12/78:20 am -
3 stops16h 52m
Deal found 11/8![Multiple Airlines logo]()
$555
This Mytrip deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/66:20 pm -
2 stops24h 35m
Wed 12/167:35 am -
2 stops17h 37m
Deal found 11/9![Multiple Airlines logo]()
$608
This Mytrip deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/24:50 pm -
2 stops24h 25m
Fri 12/114:15 pm -
3 stops19h 42m
Deal found 11/10![Multiple Airlines logo]()
$609
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 November 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 November 10, 2026.
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:13 pm -
2 stops23h 02m
Thu 12/109:10 am -
2 stops27h 07m
Deal found 11/5![Multiple Airlines logo]()
$437
This Delta deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 1/256:20 am -
2 stops10h 34m
Fri 1/296:05 am -
2 stops11h 32m
Deal found 11/9![Delta logo]()
$651
This United Airlines deal was found by Cheapflights users on 11/5. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/56:30 am -
1 stop9h 17m
Tue 12/84:30 pm -
1 stop7h 29m
Deal found 11/5![United Airlines logo]()
$705
This Gotogate deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/124:05 pm -
Nonstop2h 00m
Sun 12/132:35 pm -
1 stop4h 41m
Deal found 11/7![Air Canada logo]()
$888
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/412:02 pm -
3 stops35h 07m
Fri 12/113:15 pm -
3 stops20h 42m
Deal found 11/5![Multiple Airlines logo]()
$537
This Mytrip deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/57:54 pm -
3 stops22h 57m
Mon 12/78:20 am -
3 stops16h 52m
Deal found 11/8![Multiple Airlines logo]()
$555
This Mytrip deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/66:20 pm -
2 stops24h 35m
Wed 12/167:35 am -
2 stops17h 37m
Deal found 11/9![Multiple Airlines logo]()
$608
This United Airlines deal was found by Cheapflights users on 11/5. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/56:10 am -
2 stops14h 40m
Wed 12/93:10 pm -
1 stop26h 14m
Deal found 11/5![United Airlines logo]()
$741
This Mytrip deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/24:50 pm -
2 stops24h 25m
Fri 12/114:15 pm -
3 stops19h 42m
Deal found 11/10![Multiple Airlines logo]()
$609
This United Airlines deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/56:10 am -
1 stop14h 46m
Sat 12/126:00 am -
1 stop11h 24m
Deal found 11/7![United Airlines logo]()
$749
This Delta deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/110:29 am -
2 stops11h 30m
Sat 2/66:10 am -
2 stops11h 22m
Deal found 11/7![Delta logo]()
$843
This United Airlines deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/96:09 am -
1 stop14h 47m
Wed 12/166:00 am -
1 stop17h 22m
Deal found 11/9![United Airlines logo]()
$749
This Kiwi.com deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/256:20 pm -
1 stop18h 45m
Fri 1/16:15 am -
2 stops29h 38m
Deal found 11/10![Multiple Airlines logo]()
$641
This Air Canada deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure 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 11/10![Air Canada logo]()
$1,017
This United Airlines deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/203:03 pm -
1 stop5h 20m
Wed 1/279:45 am -
1 stop10h 42m
Deal found 11/10![United Airlines logo]()
$795
This Air Canada deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/129:40 am -
1 stop6h 02m
Sun 12/1312:05 pm -
1 stop6h 00m
Deal found 11/10![Air Canada logo]()
$1,017
This Mytrip deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/245:37 pm -
3 stops21h 57m
Thu 12/311:10 pm -
2 stops25h 11m
Deal found 11/9![Multiple Airlines logo]()
$717
This United Airlines deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/264:05 pm -
Nonstop2h 00m
Wed 12/96:45 am -
1 stop17h 14m
Deal found 11/10![United Airlines logo]()
$826
This Mytrip deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/245:37 pm -
2 stops19h 53m
Thu 12/318:25 am -
3 stops29h 56m
Deal found 11/9![Multiple Airlines logo]()
$726
This United Airlines deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/307:30 am -
1 stop5h 03m
Fri 5/76:40 pm -
1 stop5h 45m
Deal found 11/8![United Airlines logo]()
$868
This Air Canada deal was found by Cheapflights users on 11/5. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/74:05 pm -
1 stop4h 47m
Wed 12/99:15 am -
1 stop7h 11m
Deal found 11/5![Air Canada logo]()
$1,200
This Mytrip deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/1412:02 pm -
2 stops24h 32m
Mon 12/2110:29 am -
2 stops15h 12m
Deal found 11/8![Multiple Airlines logo]()
$765
This Mytrip deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/236:21 pm -
2 stops17h 29m
Wed 12/3012:15 pm -
2 stops13h 26m
Deal found 11/7![Multiple Airlines logo]()
$841
This United Airlines deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/261:00 pm -
1 stop4h 57m
Wed 12/912:05 pm -
1 stop6h 00m
Deal found 11/7![United Airlines logo]()
$1,057
This United deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/68:02 am -
1 stop9h 43m
Fri 12/112:10 pm -
Nonstop2h 16m
Deal found 11/9![Multiple Airlines logo]()
$853
This United deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/105:40 pm -
1 stop5h 19m
Sat 12/122:10 pm -
Nonstop2h 16m
Deal found 11/10![Multiple Airlines logo]()
$853
This United Airlines deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/254:05 pm -
1 stop4h 47m
Fri 1/15:30 am -
2 stops13h 48m
Deal found 11/10![United Airlines logo]()
$1,137
This KAYAK deal was found by Cheapflights users on 11/5. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/284:05 pm -
1 stop5h 31m
Wed 12/305:00 am -
1 stop11h 26m
Deal found 11/5![Air Canada logo]()
$1,792
This United deal was found by Cheapflights users on 11/5. 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 United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/25:25 am -
1 stop7h 38m
Sat 12/52:10 pm -
Nonstop2h 16m
Deal found 11/5![Multiple Airlines logo]()
$902
This United Airlines deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/74:05 pm -
1 stop4h 47m
Wed 12/93:20 pm -
2 stops8h 39m
Deal found 11/6![United Airlines logo]()
$1,299
Last-minute flights from St. Louis to OntarioDiscover last-minute flight deals from St. Louis to Ontario. Data last updated November 10, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Ontario. Data last updated November 10, 2026 and is based on user searches.
This American Airlines deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/16:00 am -
1 stop10h 40m
Mon 12/1411:36 am -
1 stop9h 22m
Deal found 11/9![American Airlines logo]()
$503
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/212:05 pm -
2 stops28h 05m
Sat 12/56:30 am -
1 stop18h 42m
Deal found 11/5![Multiple Airlines logo]()
$387
This Kiwi.com deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure 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 11/8![Multiple Airlines logo]()
$476
This Mytrip deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/24:50 pm -
2 stops24h 25m
Fri 12/114:15 pm -
3 stops19h 42m
Deal found 11/10![Multiple Airlines logo]()
$609
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:13 pm -
1 stop18h 27m
Thu 12/1012:20 pm -
2 stops23h 57m
Deal found 11/5![Multiple Airlines logo]()
$386
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:13 pm -
2 stops23h 02m
Thu 12/109:10 am -
2 stops27h 07m
Deal found 11/5![Multiple Airlines logo]()
$437
This Mytrip deal was found by Cheapflights users on 11/5. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/412:02 pm -
3 stops35h 07m
Fri 12/113:15 pm -
3 stops20h 42m
Deal found 11/5![Multiple Airlines logo]()
$537
This Mytrip deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/57:54 pm -
3 stops22h 57m
Mon 12/78:20 am -
3 stops16h 52m
Deal found 11/8![Multiple Airlines logo]()
$555
This Mytrip deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/66:20 pm -
2 stops24h 35m
Wed 12/167:35 am -
2 stops17h 37m
Deal found 11/9![Multiple Airlines logo]()
$608
This American Airlines deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/86:02 am -
1 stop7h 40m
Wed 12/93:22 pm -
1 stop9h 40m
Deal found 11/9![American Airlines logo]()
$488
This Kiwi.com deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/96:20 pm -
1 stop18h 20m
Fri 12/116:30 am -
1 stop18h 42m
Deal found 11/7![Multiple Airlines logo]()
$501
This Kiwi.com deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/912:02 pm -
2 stops35h 07m
Wed 12/168:00 am -
1 stop17h 12m
Deal found 11/9![Multiple Airlines logo]()
$548
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 November 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 November 10, 2026.
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/106:20 pm -
1 stop18h 20m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/5![Multiple Airlines logo]()
$201
This Kiwi.com deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/249:50 am -
2 stops7h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Multiple Airlines logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/306:21 pm -
2 stops26h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/7![Multiple Airlines logo]()
$211
This Kiwi.com deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure 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 11/8![Multiple Airlines logo]()
$215
This American Airlines deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/97:27 am -
1 stop9h 16m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![American Airlines logo]()
$230
This Kiwi.com deal was found by Cheapflights users on 11/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/245:58 pm -
2 stops24h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Multiple Airlines logo]()
$237
This American Airlines deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/105:02 am -
1 stop8h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![American Airlines logo]()
$245
This Kiwi.com deal was found by Cheapflights users on 11/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/247:20 pm -
2 stops21h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/10![Multiple Airlines logo]()
$246
This American Airlines deal was found by Cheapflights users on 11/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/115:02 am -
1 stop8h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![American Airlines logo]()
$255
This Kiwi.com deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/319:50 am -
2 stops7h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Multiple Airlines logo]()
$255
This Kiwi.com deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/252:00 pm -
2 stops27h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/7![Multiple Airlines logo]()
$260
This Kiwi.com deal was found by Cheapflights users on 11/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/226:20 pm -
2 stops21h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/7![Multiple Airlines logo]()
$297
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 November 10, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $371 (Kiwi.com) |
One-way from | $201 (Kiwi.com) |
Popular in | August |
Cheapest in | January |
Average price | $634 |
Good round-trip deal | $760 or less |
Good one-way deal | $437 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 November 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
Thu 12/24
9:50 am-6:15 pm
2 stops7h 25m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$202
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 12/9
12:02 pm-3:20 pm
2 stops26h 18m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$215
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Tue 11/24
7:20 pm-6:15 pm
2 stops21h 55m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$246
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Fri 12/11
5:02 am-2:42 pm
1 stop8h 40m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$255
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Thu 12/10
6:20 pm-11:47 pm
3 stops28h 27m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$263
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Thu 12/24
5:58 pm-1:40 pm
1 stop18h 42m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$268
St. LouisToronto
STL Lambert-St Louis - YTZ Toronto Island
STLYTZ
Lambert-St Louis
Mon 11/23
7:20 pm-6:15 pm
2 stops21h 55m
Toronto Island
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$299
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Mon 12/28
6:21 pm-9:55 pm
2 stops26h 34m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$305
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Tue 11/17
5:29 pm-11:46 pm
1 stop5h 17m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$310
St. LouisToronto
STL Lambert-St Louis - YYZ Toronto Pearson Intl
STLYYZ
Lambert-St Louis
Wed 11/25
6:35 pm-1:40 pm
2 stops18h 05m
Toronto Pearson Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$312
Showing 1-10 of 55 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
STL-YXU
STL-YQT
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
STL-YXU
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 November 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.
How much does it cost to fly round-trip from St. Louis to Region of Ontario?
Airfare is typical for this route at the moment.
St. Louis to Region of Ontario flights typically cost between $332 and $479 in February.The cheapest round-trip price found within the last 5 days was $371 on Multiple Airlines (Feb 10-Feb 17).
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 November 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
Crew
8.5
Entertainment
7.8
Boarding
8.1
Overall
7.8
Food
7.2
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Crew
8.5
Entertainment
7.8
Boarding
8.1
Overall
7.8
Food
7.2
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Crew
8.5
Entertainment
7.8
Boarding
8.1
Overall
7.8
Food
7.2
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Crew
8.5
Entertainment
7.8
Boarding
8.1
Overall
7.8
Food
7.2
Reviews
1 / 20
6.0
GoodEllen,Oct 2026
GRR - ATL
Comfort
7.8
Crew
8.5
Entertainment
7.8
Boarding
8.1
Overall
7.8
Food
7.2
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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St. Louis and Ontario flights
Browse other St. Louis and Ontario flight options. Last updated on November 10, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 3 airlines flying from St. Louis to Ontario
Discover the top 3 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 November 10, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$139 | Average$546 | FlexibilityNo cancel fee | On-time67% | |
| Cheapest$203 | Average$671 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$453 | Average$634 | FlexibilityNo cancel fee | On-time71% |