$82+ Cheap flights from Ontario to St. Louis (ONT - STL)
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 10/14. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — STL
Oct 22 — Oct 291
Round-trip
1 adult, Economy
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Find cheap flights from Ontario to St. Louis 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 Ontario to St. Louis
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Best
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One-way
Cheapest flights from Ontario to St. LouisExplore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 22, 2026.
Explore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 22, 2026.
This Kiwi.com deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/216:15 am -
1 stop7h 09m
Sat 10/247:42 pm -
1 stop6h 08m
Deal found 9/19![Frontier logo]()
$163
This Mytrip deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/286:25 am -
1 stop6h 58m
Mon 11/27:59 pm -
1 stop16h 36m
Deal found 9/19![Frontier logo]()
$165
This Booking.com deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/76:25 am -
1 stop10h 49m
Mon 11/97:59 pm -
1 stop5h 52m
Deal found 9/18![Frontier logo]()
$171
This Cheapflightsfares deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/1811:52 am -
1 stop20h 53m
Wed 12/27:58 pm -
1 stop16h 47m
Deal found 9/18![Frontier logo]()
$172
This Cheapflightsfares deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/36:00 am -
1 stop26h 57m
Mon 12/77:54 pm -
1 stop16h 51m
Deal found 9/20![Frontier logo]()
$188
This Booking.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:25 am -
1 stop6h 58m
Sat 11/77:59 pm -
1 stop5h 52m
Deal found 9/21![Frontier logo]()
$191
This Priceline deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2611:52 am -
1 stop5h 23m
Mon 11/27:59 pm -
1 stop5h 52m
Deal found 9/19![Frontier logo]()
$202
This Booking.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/266:15 am -
1 stop11h 00m
Sat 10/317:59 pm -
1 stop5h 52m
Deal found 9/21![Frontier logo]()
$205
This Kiwi.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” 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 10/136:15 am -
2 stops51h 16m
Sat 10/247:42 pm -
1 stop6h 08m
Deal found 9/21![Frontier logo]()
$208
Best flights from Ontario to St. LouisDiscover carefully curated flight deals from Ontario to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 22, 2026.
Discover carefully curated flight deals from Ontario to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 22, 2026.
This Southwest deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/185:45 am -
2 stops7h 35m
Thu 11/198:25 am -
1 stop8h 25m
Deal found 9/17![Southwest logo]()
$317
This Delta deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” 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 10/1712:16 pm -
1 stop9h 38m
Wed 10/217:00 pm -
1 stop6h 55m
Deal found 9/17![Delta logo]()
$323
This Cheapflightsfares deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1911:52 am -
1 stop21h 11m
Fri 11/203:04 pm -
1 stop21h 41m
Deal found 9/21![Frontier logo]()
$372
This United Airlines deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/19:25 am -
1 stop7h 18m
Tue 10/611:35 am -
2 stops11h 23m
Deal found 9/17![United Airlines logo]()
$557
This Delta deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” 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 11/2512:18 pm -
1 stop7h 24m
Thu 11/2612:29 pm -
1 stop9h 20m
Deal found 9/21![Delta logo]()
$450
This Southwest deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/198:40 am -
2 stops6h 45m
Fri 11/205:40 am -
1 stop7h 00m
Deal found 9/20![Southwest logo]()
$454
This United Airlines deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” 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 -
1 stop5h 38m
Thu 11/268:00 am -
1 stop9h 24m
Deal found 9/21![United Airlines logo]()
$569
This Delta deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 12/195:05 pm -
1 stop5h 41m
Mon 12/283:48 pm -
1 stop9h 53m
Deal found 9/20![Delta logo]()
$590
Last-minute flights from Ontario to St. LouisDiscover last-minute flight deals from Ontario to St. Louis. Data last updated September 22, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to St. Louis. Data last updated September 22, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” 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 10/136:15 am -
2 stops51h 16m
Sat 10/247:42 pm -
1 stop6h 08m
Deal found 9/21![Frontier logo]()
$208
This Kiwi.com deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/216:15 am -
1 stop7h 09m
Sat 10/247:42 pm -
1 stop6h 08m
Deal found 9/19![Frontier logo]()
$163
This Cheapflightsfares deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/246:15 am -
1 stop10h 42m
Mon 10/268:00 pm -
1 stop16h 35m
Deal found 9/18![Frontier logo]()
$212
This Priceline deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2611:52 am -
1 stop5h 23m
Mon 11/27:59 pm -
1 stop5h 52m
Deal found 9/19![Frontier logo]()
$202
This Booking.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/266:15 am -
1 stop11h 00m
Sat 10/317:59 pm -
1 stop5h 52m
Deal found 9/21![Frontier logo]()
$205
This Mytrip deal was found by Cheapflights users on 9/19. Clicking the “Pick Dates” 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 10/286:25 am -
1 stop6h 58m
Mon 11/27:59 pm -
1 stop16h 36m
Deal found 9/19![Frontier logo]()
$165
This Booking.com deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/3111:52 am -
1 stop5h 22m
Sat 11/147:59 pm -
1 stop16h 36m
Deal found 9/17![Frontier logo]()
$214
One-way flights from Ontario to St. LouisSearch for one-way flight options from Ontario to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 22, 2026.
Search for one-way flight options from Ontario to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 22, 2026.
This Booking.com deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:15 am -
1 stop7h 09m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$82
This Kiwi.com deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” 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 10/2711:52 am -
1 stop25h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$86
This Mytrip deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1011:52 am -
1 stop25h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$97
This Frontier deal was found by Cheapflights users on 9/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/216:15 am -
1 stop7h 09m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/20![Frontier logo]()
$98
This Cheapflightsfares deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/286:25 am -
1 stop6h 58m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/17![Frontier logo]()
$102
This Frontier deal was found by Cheapflights users on 9/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/46:25 am -
1 stop6h 58m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/17![Frontier logo]()
$104
This Super.com deal was found by Cheapflights users on 9/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/311:52 am -
1 stop25h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$113
This Super.com deal was found by Cheapflights users on 9/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/3011:45 am -
1 stop5h 32m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/18![Frontier logo]()
$119
Find flight deals from Ontario to St. Louis
Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 22, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $163 (Kiwi.com) |
One-way from | $82 (Booking.com) |
Popular in | July |
Cheapest in | April |
Average price | $380 |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to St. Louis 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 22, 2026.
Use the filters below to find and compare flights from Ontario to St. Louis that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Tue 10/27
9:25 am-6:05 pm
1 stop6h 40m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$134
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Tue 10/20
2:13 pm-11:59 pm
1 stop7h 46m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$134
Quickest round-trip
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Fri 10/30
11:52 am-7:14 pm
1 stop5h 22m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$138
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Fri 10/9
8:35 pm-6:57 pm
2 stops20h 22m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$184
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Fri 10/2
12:07 pm-7:17 pm
2 stops29h 10m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$191
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Tue 10/13
11:26 am-3:24 pm
2 stops25h 58m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$197
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Thu 10/22
6:00 am-1:32 pm
1 stop5h 32m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$206
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Mon 12/7
7:50 am-5:20 pm
1 stop7h 30m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$206
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Tue 11/3
5:00 am-3:43 pm
2 stops8h 43m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$225
OntarioSt. Louis
ONT Ontario - STL Lambert-St Louis
ONTSTL
Ontario
Fri 12/11
2:41 pm-10:57 am
2 stops18h 16m
Lambert-St Louis
Wed 12/31
12:00 am-10:00 pm
Nonstop0h 00m
$225
Showing 1-10 of 18 resultsSorted by cheapest first
Compare providers for flights from Ontario to St. Louis
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to St. Louis in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star |
- Most accurate provider: When it comes to deals on Ontario-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-St. Louis flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Ontario-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from Ontario to St. Louis
Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ontario with our price prediction graph.
ONT-STL
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from Ontario to St. Louis
What is the cheapest month to book a flight from Ontario to St. Louis?
Currently, April is the cheapest month in which you can book a flight from Ontario to St. Louis (average of $250). Flying from Ontario to St. Louis in July is currently the most expensive (average of $596). 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.
How much does it cost to fly round-trip from Ontario to St. Louis?
Airfare is below average for this route at the moment.
Ontario to St. Louis flights typically cost between $306 and $469 in October.The cheapest round-trip price found within the last 5 days was $163 on Frontier (Oct 21-Oct 24).
Reviews of airlines servicing St. Louis
Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated September 22, 2026.
Get a feel of what it's like to fly with Southwest,Delta, andUnited Airlines from Ontario to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Comfort
8.0
Entertainment
7.5
Food
7.0
Overall
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Related info for your journey
Find useful and relevant information for your journey from Ontario to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsFairview Heights
O'Fallon
Fenton
Swansea
Eureka
Wentzville
Maryland Heights
Collinsville
Edwardsville
Glencoe
Chesterfield
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Alternative routes for Ontario to St. Louis
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Ontario and St. Louis flights
Browse other Ontario and St. Louis flight options. Last updated on September 22, 2026.
Other flights from Ontario
Browse through other flights departing from Ontario. Flights are based on user searches made on Cheapflights and were last updated on September 22, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Other flights to St. Louis
Explore flights to St. Louis departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 22, 2026.
Top 5 airlines flying from Ontario to St. Louis
Discover the top 5 airlines that operate flights from Ontario to St. Louis. 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 22, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$105 | Average$266 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$165 | Average$437 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$292 | Average$556 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$292 | Average$447 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$346 | Average$489 | FlexibilityNo cancel fee | On-time63% |