$184+ Cheap flights from St. Louis (STL) to Ottawa (YOW)
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 9/30. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YOW
Sep 15 — Sep 221
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Ottawa 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 St. Louis to Ottawa
Cheapest
Best
Last-minute
One-way
Cheapest flights from St. Louis to OttawaExplore the most affordable flight options available from St. Louis to Ottawa. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 16, 2026.
Explore the most affordable flight options available from St. Louis to Ottawa. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 16, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/13. 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 9/106:39 pm -
1 stop18h 54m
Thu 9/178:15 pm -
2 stops17h 55m
Deal found 8/13![Multiple Airlines logo]()
$463
This Kiwi.com deal was found by Cheapflights users on 8/11. 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 9/2212:17 pm -
2 stops16h 18m
Fri 9/257:00 am -
1 stop10h 34m
Deal found 8/11![Multiple Airlines logo]()
$533
This Air Canada deal was found by Cheapflights users on 8/12. 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 9/2212:10 pm -
1 stop6h 35m
Fri 9/252:45 pm -
1 stop4h 56m
Deal found 8/12![Air Canada logo]()
$574
This Air Canada deal was found by Cheapflights users on 8/11. 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 9/182:40 pm -
1 stop5h 40m
Sun 9/209:00 am -
1 stop6h 00m
Deal found 8/11![Air Canada logo]()
$584
This Kiwi.com deal was found by Cheapflights users on 8/13. 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 10/16:39 pm -
1 stop18h 54m
Tue 10/62:10 pm -
2 stops24h 00m
Deal found 8/13![Multiple Airlines logo]()
$586
This United Airlines deal was found by Cheapflights users on 8/12. 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 9/228:30 am -
2 stops9h 25m
Fri 9/255:20 pm -
1 stop5h 01m
Deal found 8/12![United Airlines logo]()
$594
This Kiwi.com deal was found by Cheapflights users on 8/14. 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.
Sun 9/275:19 pm -
1 stop29h 29m
Thu 10/18:15 pm -
2 stops17h 55m
Deal found 8/14![Multiple Airlines logo]()
$600
This Kiwi.com deal was found by Cheapflights users on 8/11. 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 9/185:19 pm -
1 stop20h 14m
Sun 9/207:00 am -
2 stops10h 34m
Deal found 8/11![Multiple Airlines logo]()
$613
This oojo deal was found by Cheapflights users on 8/12. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/221:55 pm -
2 stops14h 40m
Fri 9/258:15 pm -
2 stops17h 17m
Deal found 8/12![WestJet logo]()
$619
Best flights from St. Louis to OttawaDiscover carefully curated flight deals from St. Louis to Ottawa that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 16, 2026.
Discover carefully curated flight deals from St. Louis to Ottawa that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 16, 2026.
This Air Canada deal was found by Cheapflights users on 8/12. 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 9/2212:10 pm -
1 stop6h 35m
Fri 9/252:45 pm -
1 stop4h 56m
Deal found 8/12![Air Canada logo]()
$574
This oojo deal was found by Cheapflights users on 8/15. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/16:40 am -
2 stops21h 55m
Tue 10/68:15 pm -
2 stops13h 54m
Deal found 8/15![WestJet logo]()
$647
This United Airlines deal was found by Cheapflights users on 8/12. 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 10/107:30 am -
1 stop8h 08m
Mon 10/125:10 am -
2 stops17h 11m
Deal found 8/12![United Airlines logo]()
$684
This United deal was found by Cheapflights users on 8/14. 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 9/273:11 pm -
1 stop5h 24m
Thu 10/12:35 pm -
1 stop5h 06m
Deal found 8/14![Multiple Airlines logo]()
$694
This oojo deal was found by Cheapflights users on 8/14. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/276:40 am -
2 stops21h 55m
Thu 10/112:25 pm -
2 stops11h 51m
Deal found 8/14![WestJet logo]()
$681
This Air Canada deal was found by Cheapflights users on 8/15. 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 10/2412:10 pm -
1 stop4h 19m
Wed 10/2810:05 am -
1 stop6h 21m
Deal found 8/15![Air Canada logo]()
$697
This United deal was found by Cheapflights users on 8/11. 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 9/239:43 am -
1 stop6h 33m
Sat 9/2610:00 am -
1 stop5h 00m
Deal found 8/11![Multiple Airlines logo]()
$698
This United Airlines deal was found by Cheapflights users on 8/11. 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 9/239:43 am -
1 stop6h 33m
Sun 9/276:00 am -
1 stop4h 41m
Deal found 8/11![United Airlines logo]()
$700
This oojo deal was found by Cheapflights users on 8/11. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/234:59 pm -
2 stops25h 21m
Sun 9/274:15 pm -
2 stops32h 01m
Deal found 8/11![WestJet logo]()
$702
Last-minute flights from St. Louis to OttawaDiscover last-minute flight deals from St. Louis to Ottawa. Data last updated August 16, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Ottawa. Data last updated August 16, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 8/13. 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 9/106:39 pm -
1 stop18h 54m
Thu 9/178:15 pm -
2 stops17h 55m
Deal found 8/13![Multiple Airlines logo]()
$463
This Air Canada deal was found by Cheapflights users on 8/11. 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 9/182:40 pm -
1 stop5h 40m
Sun 9/209:00 am -
1 stop6h 00m
Deal found 8/11![Air Canada logo]()
$584
This Kiwi.com deal was found by Cheapflights users on 8/11. 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 9/185:19 pm -
1 stop20h 14m
Sun 9/207:00 am -
2 stops10h 34m
Deal found 8/11![Multiple Airlines logo]()
$613
This Kiwi.com deal was found by Cheapflights users on 8/11. 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 9/2212:17 pm -
2 stops16h 18m
Fri 9/257:00 am -
1 stop10h 34m
Deal found 8/11![Multiple Airlines logo]()
$533
This Air Canada deal was found by Cheapflights users on 8/12. 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 9/2212:10 pm -
1 stop6h 35m
Fri 9/252:45 pm -
1 stop4h 56m
Deal found 8/12![Air Canada logo]()
$574
This United Airlines deal was found by Cheapflights users on 8/12. 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 9/228:30 am -
2 stops9h 25m
Fri 9/255:20 pm -
1 stop5h 01m
Deal found 8/12![United Airlines logo]()
$594
This oojo deal was found by Cheapflights users on 8/12. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/221:55 pm -
2 stops14h 40m
Fri 9/258:15 pm -
2 stops17h 17m
Deal found 8/12![WestJet logo]()
$619
This Kiwi.com deal was found by Cheapflights users on 8/14. 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.
Sun 9/275:19 pm -
1 stop29h 29m
Thu 10/18:15 pm -
2 stops17h 55m
Deal found 8/14![Multiple Airlines logo]()
$600
One-way flights from St. Louis to OttawaSearch for one-way flight options from St. Louis to Ottawa. Find affordable one-way fares based on user searches. Data last updated August 16, 2026.
Search for one-way flight options from St. Louis to Ottawa. Find affordable one-way fares based on user searches. Data last updated August 16, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/16. 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 9/302:29 pm -
3 stops32h 51m
Deal found 8/16![Multiple Airlines logo]()
$184
This United Airlines deal was found by Cheapflights users on 8/16. 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 9/309:30 am -
1 stop6h 08m
Deal found 8/16![United Airlines logo]()
$321
Find flight deals from St. Louis to Ottawa
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Ottawa (YOW). 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 16, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $463 (Kiwi.com) |
Popular in | December |
Cheapest in | June |
Average price | $489 |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Ottawa 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 August 16, 2026.
Use the filters below to find and compare flights from St. Louis to Ottawa that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Tue 9/22
12:10 pm-7:45 pm
1 stop6h 35m
Ottawa
Fri 9/25
2:45 pm-6:41 pm
1 stop4h 56m
$574
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Thu 10/1
6:40 am-5:35 am
2 stops21h 55m
Ottawa
Tue 10/6
8:15 pm-9:09 am
2 stops13h 54m
$647
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Sun 9/27
6:40 am-5:35 am
2 stops21h 55m
Ottawa
Thu 10/1
12:25 pm-11:16 pm
2 stops11h 51m
$681
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Sat 10/10
7:30 am-4:38 pm
1 stop8h 08m
Ottawa
Mon 10/12
5:10 am-9:21 pm
2 stops17h 11m
$684
Quickest round-trip
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Sun 9/27
3:11 pm-9:35 pm
1 stop5h 24m
Ottawa
Thu 10/1
2:35 pm-6:41 pm
1 stop5h 06m
$694
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Sat 10/24
12:10 pm-5:29 pm
1 stop4h 19m
Ottawa
Wed 10/28
10:05 am-3:26 pm
1 stop6h 21m
$697
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Wed 9/23
9:43 am-5:16 pm
1 stop6h 33m
Ottawa
Sat 9/26
10:00 am-2:00 pm
1 stop5h 00m
$698
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Wed 9/23
9:43 am-5:16 pm
1 stop6h 33m
Ottawa
Sun 9/27
6:00 am-9:41 am
1 stop4h 41m
$700
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Wed 9/23
4:59 pm-7:20 pm
2 stops25h 21m
Ottawa
Sun 9/27
4:15 pm-11:16 pm
2 stops32h 01m
$702
Cheapest one-way
St. LouisOttawa
STL Lambert-St Louis - YOW Ottawa
STLYOW
Lambert-St Louis
Wed 9/30
2:29 pm-12:20 am
3 stops32h 51m
$184
Showing 1-10 of 11 resultsSorted by cheapest first
- Most accurate provider: When it comes to deals on St. Louis-Ottawa flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Ottawa flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Ottawa flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Ottawa 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 St. Louis-Ottawa 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 St. Louis to Ottawa
Have a flexible travel schedule? Discover the best time to fly to Ottawa from St. Louis with our price prediction graph.
STL-YOW
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 Ottawa
Reviews of airlines servicing Ottawa
Get insights into the airlines that provide service to Ottawa. 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 Ottawa. Reviews last updated August 16, 2026.
Get a feel of what it's like to fly with United Airlines and Air Canada from St. Louis to Ottawa by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
7.3
Food
6.7
Overall
7.4
Boarding
7.7
Entertainment
7.1
Crew
8.1
Reviews
1 / 20
6.0
GoodMiz,Oct 2024
EWR - YYZ
Comfort
7.3
Food
6.7
Overall
7.4
Boarding
7.7
Entertainment
7.1
Crew
8.1
Reviews
1 / 20
6.0
GoodMiz,Oct 2024
EWR - YYZ
Comfort
7.3
Food
6.7
Overall
7.4
Boarding
7.7
Entertainment
7.1
Crew
8.1
Reviews
1 / 20
6.0
GoodMiz,Oct 2024
EWR - YYZ
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Ottawa. 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 Ottawa?
Book flights to Ottawa if you plan to visit one of these locationsGatineau
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St. Louis and Ottawa flights
Browse other St. Louis and Ottawa flight options. Last updated on August 16, 2026.
Other flights from St. Louis
Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on August 16, 2026.
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Explore flights to Ottawa departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on August 16, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 2 airlines flying from St. Louis to Ottawa
Discover the top 2 airlines that operate flights from St. Louis to Ottawa. 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 August 16, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$139 | Average$404 | FlexibilityNo cancel fee | On-time67% | |
| Cheapest$203 | Average$483 | FlexibilityNo cancel fee | On-time69% |