$246+ Cheap flights from Ottawa (YOW) to St. Louis (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 1/29. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
Nov 25 — Dec 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 October 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 October 26, 2026.
This Kiwi.com deal was found by Cheapflights users on 10/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/98:00 am -
1 stop17h 12m
Wed 12/166:20 pm -
2 stops21h 55m
Deal found 10/25![Multiple Airlines logo]()
$513
This Mytrip deal was found by Cheapflights users on 10/22. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/267:00 am -
3 stops29h 03m
Mon 11/306:35 pm -
3 stops22h 21m
Deal found 10/22![Multiple Airlines logo]()
$612
This Kiwi.com deal was found by Cheapflights users on 10/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/218:00 am -
1 stop16h 59m
Sat 11/286:05 pm -
2 stops22h 10m
Deal found 10/24![Multiple Airlines logo]()
$653
This Air Canada deal was found by Cheapflights users on 10/25. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/2910:05 am -
1 stop6h 21m
Mon 1/44:05 pm -
1 stop5h 50m
Deal found 10/25![Air Canada logo]()
$657
This United Airlines deal was found by Cheapflights users on 10/22. 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 11/213:10 pm -
1 stop8h 44m
Sat 11/288:30 am -
2 stops12h 26m
Deal found 10/22![United Airlines logo]()
$671
This United deal was found by Cheapflights users on 10/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/296:00 am -
2 stops12h 08m
Mon 1/44:05 pm -
1 stop5h 50m
Deal found 10/25![Multiple Airlines logo]()
$675
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 October 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 October 26, 2026.
This Kiwi.com deal was found by Cheapflights users on 10/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/98:00 am -
1 stop17h 12m
Wed 12/166:20 pm -
2 stops21h 55m
Deal found 10/25![Multiple Airlines logo]()
$513
This United Airlines deal was found by Cheapflights users on 10/22. 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 11/213:10 pm -
1 stop8h 44m
Sat 11/286:00 am -
1 stop14h 16m
Deal found 10/22![United Airlines logo]()
$671
This United deal was found by Cheapflights users on 10/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/296:00 am -
2 stops12h 08m
Mon 1/44:05 pm -
1 stop5h 50m
Deal found 10/25![Multiple Airlines logo]()
$675
This United Airlines deal was found by Cheapflights users on 10/25. 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.
Tue 12/86:15 am -
1 stop14h 11m
Fri 12/116:30 am -
1 stop6h 39m
Deal found 10/25![United Airlines logo]()
$688
This Air Canada deal was found by Cheapflights users on 10/22. 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 11/263:10 pm -
1 stop18h 43m
Mon 11/304:05 pm -
1 stop4h 45m
Deal found 10/22![Multiple Airlines logo]()
$691
This United Airlines deal was found by Cheapflights users on 10/24. 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 11/266:15 am -
1 stop6h 55m
Mon 11/306:00 am -
1 stop7h 09m
Deal found 10/24![United Airlines logo]()
$696
Last-minute flights from Ottawa to St. LouisDiscover last-minute flight deals from Ottawa to St. Louis. Data last updated October 26, 2026 and is based on user searches.
Discover last-minute flight deals from Ottawa to St. Louis. Data last updated October 26, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 10/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/218:00 am -
1 stop16h 59m
Sat 11/286:05 pm -
2 stops22h 10m
Deal found 10/24![Multiple Airlines logo]()
$653
This United Airlines deal was found by Cheapflights users on 10/22. 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 11/213:10 pm -
1 stop8h 44m
Sat 11/288:30 am -
2 stops12h 26m
Deal found 10/22![United Airlines logo]()
$671
This Mytrip deal was found by Cheapflights users on 10/22. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/267:00 am -
3 stops29h 03m
Mon 11/306:35 pm -
3 stops22h 21m
Deal found 10/22![Multiple Airlines logo]()
$612
This United Airlines deal was found by Cheapflights users on 10/22. 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.
Thu 11/266:15 am -
1 stop10h 28m
Mon 11/306:50 pm -
2 stops17h 21m
Deal found 10/22![United Airlines logo]()
$703
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 October 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 October 26, 2026.
This Kiwi.com deal was found by Cheapflights users on 10/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/2912:00 pm -
3 stops37h 04m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/24![Multiple Airlines logo]()
$246
This United Airlines deal was found by Cheapflights users on 10/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/296:15 am -
1 stop12h 35m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/24![United Airlines logo]()
$374
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 October 26, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $513 (Kiwi.com) |
One-way from | $246 (Kiwi.com) |
Popular in | August |
Cheapest in | May |
Average price | $659 |
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 October 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
Fri 1/29
12:00 pm-12:04 am
3 stops37h 04m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$246
Quickest round-trip
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Fri 1/29
6:15 am-5:50 pm
1 stop12h 35m
Lambert-St Louis
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$374
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Wed 12/9
8:00 am-12:12 am
1 stop17h 12m
Lambert-St Louis
Wed 12/16
6:20 pm-5:15 pm
2 stops21h 55m
$513
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Sat 11/21
3:10 pm-10:54 pm
1 stop8h 44m
Lambert-St Louis
Sat 11/28
6:00 am-9:16 pm
1 stop14h 16m
$671
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Tue 12/29
6:00 am-5:08 pm
2 stops12h 08m
Lambert-St Louis
Mon 1/4
4:05 pm-10:55 pm
1 stop5h 50m
$675
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Tue 12/8
6:15 am-7:26 pm
1 stop14h 11m
Lambert-St Louis
Fri 12/11
6:30 am-2:09 pm
1 stop6h 39m
$688
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 11/26
3:10 pm-8:53 am
1 stop18h 43m
Lambert-St Louis
Mon 11/30
4:05 pm-9:50 pm
1 stop4h 45m
$691
OttawaSt. Louis
YOW Ottawa - STL Lambert-St Louis
YOWSTL
Ottawa
Thu 11/26
6:15 am-12:10 pm
1 stop6h 55m
Lambert-St Louis
Mon 11/30
6:00 am-2:09 pm
1 stop7h 09m
$696
Sorted by cheapest first
Compare providers for flights from Ottawa 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 Ottawa to St. Louis in October.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*3 stars |
- 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 October 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.
Food
6.3
Entertainment
6.8
Overall
7.1
Crew
7.8
Comfort
7.1
Boarding
7.3
Reviews
1 / 20
2.0
MediocreSylvia,Aug 2026
YYZ - PHL
Food
6.3
Entertainment
6.8
Overall
7.1
Crew
7.8
Comfort
7.1
Boarding
7.3
Reviews
1 / 20
2.0
MediocreSylvia,Aug 2026
YYZ - PHL
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 locationsFairview Heights
O'Fallon
Fenton
Swansea
Eureka
Wentzville
Maryland Heights
Chesterfield
Collinsville
Edwardsville
Glencoe
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Ottawa and St. Louis flights
Browse other Ottawa and St. Louis flight options. Last updated on October 26, 2026.
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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 October 26, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$285 | Average$375 | FlexibilityNo cancel fee | On-time67% |