$255+ 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 9/10. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
Sep 25 — Oct 21
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
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 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 August 26, 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 August 26, 2026.
This United Airlines deal was found by Cheapflights users on 8/26. 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.
Wed 9/236:25 am -
1 stop6h 32m
Wed 9/309:30 am -
1 stop12h 05m
Deal found 8/26![United Airlines logo]()
$493
This United Airlines deal was found by Cheapflights users on 8/24. 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.
Thu 9/245:20 pm -
1 stop5h 01m
Mon 9/287:30 am -
1 stop14h 05m
Deal found 8/24![United Airlines logo]()
$494
This United Airlines deal was found by Cheapflights users on 8/23. 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 11/43:10 pm -
2 stops9h 14m
Mon 11/99:40 am -
1 stop10h 36m
Deal found 8/23![United Airlines logo]()
$561
This Delta deal was found by Cheapflights users on 8/24. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/246:55 am -
2 stops11h 50m
Mon 9/282:30 pm -
2 stops8h 50m
Deal found 8/24![Delta logo]()
$571
This FlightHub deal was found by Cheapflights users on 8/23. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/176:55 am -
2 stops10h 33m
Sun 10/186:47 am -
2 stops21h 48m
Deal found 8/23![WestJet logo]()
$618
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 August 26, 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 August 26, 2026.
This United Airlines deal was found by Cheapflights users on 8/26. 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.
Wed 9/236:25 am -
1 stop6h 32m
Wed 9/309:30 am -
1 stop12h 05m
Deal found 8/26![United Airlines logo]()
$493
This Delta deal was found by Cheapflights users on 8/24. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/246:55 am -
2 stops11h 50m
Mon 9/282:30 pm -
2 stops8h 50m
Deal found 8/24![Delta logo]()
$571
This United Airlines deal was found by Cheapflights users on 8/25. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/245:20 pm -
1 stop5h 01m
Mon 9/287:30 am -
1 stop14h 05m
Deal found 8/25![United Airlines logo]()
$493
This United Airlines deal was found by Cheapflights users on 8/23. 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.
Sat 10/176:00 am -
2 stops9h 16m
Sun 10/189:04 am -
1 stop11h 31m
Deal found 8/23![United Airlines logo]()
$561
This United Airlines deal was found by Cheapflights users on 8/23. 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 11/46:15 am -
1 stop10h 28m
Mon 11/97:30 am -
1 stop5h 39m
Deal found 8/23![United Airlines logo]()
$561
Last-minute flights from Ottawa to St. LouisDiscover last-minute flight deals from Ottawa to St. Louis. Data last updated August 26, 2026 and is based on user searches.
Discover last-minute flight deals from Ottawa to St. Louis. Data last updated August 26, 2026 and is based on user searches.
This United Airlines deal was found by Cheapflights users on 8/22. 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.
Wed 8/266:05 am -
1 stop6h 12m
Sun 9/271:29 pm -
1 stop7h 06m
Deal found 8/22![United Airlines logo]()
$772
This United Airlines deal was found by Cheapflights users on 8/26. 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.
Wed 9/236:25 am -
1 stop6h 32m
Wed 9/309:30 am -
1 stop12h 05m
Deal found 8/26![United Airlines logo]()
$493
This United Airlines deal was found by Cheapflights users on 8/24. 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.
Thu 9/245:20 pm -
1 stop5h 01m
Mon 9/287:30 am -
1 stop14h 05m
Deal found 8/24![United Airlines logo]()
$494
This Delta deal was found by Cheapflights users on 8/24. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/246:55 am -
2 stops11h 50m
Mon 9/282:30 pm -
2 stops8h 50m
Deal found 8/24![Delta logo]()
$571
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 August 26, 2026.
Search for one-way flight options from Ottawa to St. Louis. Find affordable one-way fares based on user searches. Data last updated August 26, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/22. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/106:55 am -
3 stops31h 15m
Deal found 8/22![Multiple Airlines logo]()
$255
This Air Canada deal was found by Cheapflights users on 8/22. 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.
Thu 9/103:10 pm -
1 stop4h 31m
Deal found 8/22![Air Canada logo]()
$357
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 August 26, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $481 (Kiwi.com) |
One-way from | $255 (Kiwi.com) |
Popular in | August |
Cheapest in | May |
Average price | $807 |
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 7,457,451 searches. Data last updated August 26, 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 Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Wed 9/23
6:25 am-11:57 am
1 stop6h 32m
Lambert-St Louis
Wed 9/30
9:30 am-10:35 pm
1 stop12h 05m
$493
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 9/24
5:20 pm-9:21 pm
1 stop5h 01m
Lambert-St Louis
Mon 9/28
7:30 am-10:35 pm
1 stop14h 05m
$493
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Sat 10/17
6:00 am-2:16 pm
2 stops9h 16m
Lambert-St Louis
Sun 10/18
9:04 am-9:35 pm
1 stop11h 31m
$561
Quickest round-trip
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Wed 11/4
6:15 am-3:43 pm
1 stop10h 28m
Lambert-St Louis
Mon 11/9
7:30 am-2:09 pm
1 stop5h 39m
$561
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 9/24
6:55 am-5:45 pm
2 stops11h 50m
Lambert-St Louis
Mon 9/28
2:30 pm-12:20 am
2 stops8h 50m
$571
Cheapest one-way
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 9/10
6:55 am-1:10 pm
3 stops31h 15m
$255
Quickest one-way
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 9/10
3:10 pm-6:41 pm
1 stop4h 31m
$357
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 August 26, 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.
Comfort
7.1
Food
6.3
Crew
7.8
Boarding
7.3
Entertainment
6.8
Overall
7.1
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
YYZ - LAS
Comfort
7.1
Food
6.3
Crew
7.8
Boarding
7.3
Entertainment
6.8
Overall
7.1
Reviews
1 / 20
10.0
ExcellentAnonymous,Nov 2025
YYZ - LAS
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
Fairview Heights
O'Fallon
Fenton
Swansea
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
Farmington
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Alternative routes for Ottawa to St. Louis
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Ottawa and St. Louis flights
Browse other Ottawa and St. Louis flight options. Last updated on August 26, 2026.
Other flights from Ottawa
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Other flights to St. Louis
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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 7,457,451 searches. Data last updated August 26, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$285 | Average$352 | FlexibilityNo cancel fee | On-time67% |