$188+ Cheap flights from Ottawa (YOW) to St. Louis (STL)
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 6/4. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
May 23 — May 301
Round-trip
1 adult, Economy
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Find cheap flights from Ottawa 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
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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 Ottawa to St. Louis
Cheapest
Best
Last-minute
One-way
Cheapest flights from Ottawa to St. LouisExplore the most affordable flight options available from Ottawa to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 23, 2026.
Explore the most affordable flight options available from Ottawa to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 23, 2026.
This Trip.com deal was found by Cheapflights users on 4/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/277:00 am
YOW
- STL
1 stop6h 21m
Air Canada
Sun 6/282:15 pm
STL
- YOW
1 stop6h 00m
Air Canada
Deal found 4/19![Air Canada logo]()
$302
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/202:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/20![Air Canada logo]()
$314
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/182:00 pm
YOW
- STL
1 stop7h 09m
Air Canada
Mon 5/257:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/20![Air Canada logo]()
$319
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/205:25 pm
YOW
- STL
1 stop6h 25m
United Airlines
Wed 5/276:00 am
STL
- YOW
2 stops7h 17m
United Airlines
Deal found 4/20![United Airlines logo]()
$320
This Air Canada deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/232:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/22![Air Canada logo]()
$327
This United Airlines deal was found by Cheapflights users on 4/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/15:50 pm
YOW
- STL
1 stop7h 07m
United Airlines
Tue 5/56:30 am
STL
- YOW
1 stop14h 05m
United Airlines
Deal found 4/18![United Airlines logo]()
$381
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:00 pm
YOW
- STL
2 stops10h 13m
United Airlines
Mon 5/257:05 am
STL
- YOW
1 stop5h 00m
United Airlines
Deal found 4/20![United Airlines logo]()
$390
This Delta deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/2312:25 pm
YOW
- STL
2 stops11h 56m
Delta
Wed 5/276:45 am
STL
- YOW
2 stops9h 50m
Delta
Deal found 4/22![Delta logo]()
$400
Best flights from Ottawa to St. LouisDiscover carefully curated flight deals from Ottawa to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 23, 2026.
Discover carefully curated flight deals from Ottawa to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 23, 2026.
This Trip.com deal was found by Cheapflights users on 4/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/277:00 am
YOW
- STL
1 stop6h 21m
Air Canada
Sun 6/282:15 pm
STL
- YOW
1 stop6h 00m
Air Canada
Deal found 4/19![Air Canada logo]()
$302
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/205:25 pm
YOW
- STL
1 stop6h 25m
United Airlines
Wed 5/276:00 am
STL
- YOW
2 stops7h 17m
United Airlines
Deal found 4/20![United Airlines logo]()
$320
This Delta deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/2312:25 pm
YOW
- STL
2 stops11h 56m
Delta
Wed 5/276:45 am
STL
- YOW
2 stops9h 50m
Delta
Deal found 4/22![Delta logo]()
$400
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/202:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/20![Air Canada logo]()
$314
This Air Canada deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/232:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/22![Air Canada logo]()
$327
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:00 pm
YOW
- STL
2 stops10h 13m
United Airlines
Mon 5/257:05 am
STL
- YOW
1 stop5h 00m
United Airlines
Deal found 4/20![United Airlines logo]()
$390
This United Airlines deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 6/65:20 pm
YOW
- STL
1 stop4h 56m
United Airlines
Sat 6/136:00 am
STL
- YOW
2 stops8h 11m
United Airlines
Deal found 4/22![United Airlines logo]()
$403
This Delta deal was found by Cheapflights users on 4/20. 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.
Mon 5/186:55 am
YOW
- STL
2 stops11h 35m
Delta
Mon 5/258:53 am
STL
- YOW
2 stops14h 27m
Delta
Deal found 4/20![Delta logo]()
$457
Last-minute flights from Ottawa to St. LouisDiscover last-minute flight deals from Ottawa to St. Louis. Data last updated April 23, 2026 and is based on user searches.
Discover last-minute flight deals from Ottawa to St. Louis. Data last updated April 23, 2026 and is based on user searches.
This United Airlines deal was found by Cheapflights users on 4/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/15:50 pm
YOW
- STL
1 stop7h 07m
United Airlines
Tue 5/56:30 am
STL
- YOW
1 stop14h 05m
United Airlines
Deal found 4/18![United Airlines logo]()
$381
This Air Canada deal was found by Cheapflights users on 4/19. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/12:00 pm
YOW
- STL
1 stop7h 09m
Air Canada
Tue 5/56:30 am
STL
- YOW
2 stops6h 29m
Air Canada
Deal found 4/19![Air Canada logo]()
$441
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/182:00 pm
YOW
- STL
1 stop7h 09m
Air Canada
Mon 5/257:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/20![Air Canada logo]()
$319
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1812:00 pm
YOW
- STL
2 stops10h 13m
United Airlines
Mon 5/257:05 am
STL
- YOW
1 stop5h 00m
United Airlines
Deal found 4/20![United Airlines logo]()
$390
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/202:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/20![Air Canada logo]()
$314
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/205:25 pm
YOW
- STL
1 stop6h 25m
United Airlines
Wed 5/276:00 am
STL
- YOW
2 stops7h 17m
United Airlines
Deal found 4/20![United Airlines logo]()
$320
This Air Canada deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/232:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Wed 5/277:05 am
STL
- YOW
1 stop5h 00m
Air Canada
Deal found 4/22![Air Canada logo]()
$327
This Delta deal was found by Cheapflights users on 4/22. Clicking the “Pick Dates” 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 5/2312:25 pm
YOW
- STL
2 stops11h 56m
Delta
Wed 5/276:45 am
STL
- YOW
2 stops9h 50m
Delta
Deal found 4/22![Delta logo]()
$400
One-way flights from Ottawa to St. LouisSearch for one-way flight options from Ottawa to St. Louis. Find affordable one-way fares based on user searches. Data last updated April 23, 2026.
Search for one-way flight options from Ottawa to St. Louis. Find affordable one-way fares based on user searches. Data last updated April 23, 2026.
This Air Canada deal was found by Cheapflights users on 4/20. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/42:40 pm
YOW
- STL
1 stop6h 45m
Air Canada
Deal found 4/20![Air Canada logo]()
$188
This United Airlines deal was found by Cheapflights users on 4/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/45:05 am
YOW
- STL
2 stops8h 06m
United Airlines
Deal found 4/20![United Airlines logo]()
$225
This Kiwi.com deal was found by Cheapflights users on 4/20. 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.
Thu 6/47:00 am
YOW
- STL
3 stops37h 23m
Multiple Airlines
Deal found 4/20![Multiple Airlines logo]()
$231
Find flight deals from Ottawa to St. Louis
Discover tips and strategies to find the most affordable flight options for your journey from Ottawa (YOW) 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 April 23, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $302 (Trip.com) |
One-way from | $188 (Air Canada) |
Popular in | March |
Cheapest in | April |
Average price | $394 |
Cheapflights Fare Finder
Customize your flight search to find flights from Ottawa 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 2,558,603 searches. Data last updated April 23, 2026.
Use the filters below to find and compare flights from Ottawa to St. Louis that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Sat 6/27
7:00 am-12:21 pm
1 stop6h 21m
Lambert-St Louis
Sun 6/28
2:15 pm-9:15 pm
1 stop6h 00m
$302
Quickest round-trip
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Wed 5/20
2:40 pm-8:25 pm
1 stop6h 45m
Lambert-St Louis
Wed 5/27
7:05 am-1:05 pm
1 stop5h 00m
$314
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Wed 5/20
5:25 pm-10:50 pm
1 stop6h 25m
Lambert-St Louis
Wed 5/27
6:00 am-2:17 pm
2 stops7h 17m
$320
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Sat 5/23
2:40 pm-8:25 pm
1 stop6h 45m
Lambert-St Louis
Wed 5/27
7:05 am-1:05 pm
1 stop5h 00m
$327
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Mon 5/18
12:00 pm-9:13 pm
2 stops10h 13m
Lambert-St Louis
Mon 5/25
7:05 am-1:05 pm
1 stop5h 00m
$390
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Sat 5/23
12:25 pm-11:21 pm
2 stops11h 56m
Lambert-St Louis
Wed 5/27
6:45 am-5:35 pm
2 stops9h 50m
$400
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Sat 6/6
5:20 pm-9:16 pm
1 stop4h 56m
Lambert-St Louis
Sat 6/13
6:00 am-3:11 pm
2 stops8h 11m
$403
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Mon 5/18
6:55 am-5:30 pm
2 stops11h 35m
Lambert-St Louis
Mon 5/25
8:53 am-12:20 am
2 stops14h 27m
$457
Cheapest one-way
Quickest one-way
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Thu 6/4
5:05 am-12:11 pm
2 stops8h 06m
$225
OttawaSt. Louis
YOW - STL
YOWSTL
Ottawa
Thu 6/4
7:00 am-7:23 pm
3 stops37h 23m
$231
Sorted by cheapest first
- Most accurate provider: When it comes to deals on Ottawa-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ottawa-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ottawa-St. Louis flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Ottawa-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 Ottawa-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 Ottawa to St. Louis
Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ottawa with our price prediction graph.
YOW-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 Ottawa to St. Louis
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 April 23, 2026.
Read through reviews of airlines operating flights from Ottawa to St. Louis, such as Air Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Crew
7.8
Overall
7.1
Food
6.3
Entertainment
6.8
Comfort
7.1
Boarding
7.3
Reviews
1 / 20
6.0
GoodThomas,Apr 2026
YYZ - LHR
Crew
7.8
Overall
7.1
Food
6.3
Entertainment
6.8
Comfort
7.1
Boarding
7.3
Reviews
1 / 20
6.0
GoodThomas,Apr 2026
YYZ - LHR
Related info for your journey
Find useful and relevant information for your journey from Ottawa 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 locationsEdwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
Chesterfield
Alton
Farmington
Festus
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Ottawa and St. Louis flights
Browse other Ottawa and St. Louis flight options. Last updated on April 23, 2026.
Other flights from Ottawa
Browse through other flights departing from Ottawa. Flights are based on user searches made on Cheapflights and were last updated on April 23, 2026.
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Check out other popular destinations found by fellow travelers in 2026
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Explore flights to St. Louis departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on April 23, 2026.
Top airline flying from Ottawa to St. Louis
Discover the top airline that operate flights from Ottawa 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 2,558,603 searches. Data last updated April 23, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$285 | Average$511 | FlexibilityNo cancel fee | On-time67% |