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$215+ 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 8/12. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YOW
Jul 29 — Aug 51
Wed 7/29
Wed 8/5
1 adult, Economy
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Cheap flight deals from St. Louis to Ottawa

Cheapest flights from St. Louis to Ottawa
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 June 29, 2026.

This Air Canada deal was found by Cheapflights users on 6/25. 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.
Sat 8/112:10 pm
STL
-
YOW
1 stop6h 35m
Air Canada
Tue 8/42:35 pm
YOW
-
STL
1 stop5h 07m
Air Canada
Deal found 6/25$489
This Air Canada deal was found by Cheapflights users on 6/24. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/812:10 pm
STL
-
YOW
1 stop6h 35m
Air Canada
Wed 8/124:00 pm
YOW
-
STL
1 stop5h 24m
Air Canada
Deal found 6/24$494
This United Airlines deal was found by Cheapflights users on 6/28. 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 8/1212:59 pm
STL
-
YOW
1 stop7h 36m
United Airlines
Wed 8/196:25 am
YOW
-
STL
1 stop10h 13m
United Airlines
Deal found 6/28$497
This United deal was found by Cheapflights users on 6/25. 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.
Sat 8/16:00 am
STL
-
YOW
2 stops7h 17m
Multiple Airlines
Tue 8/42:35 pm
YOW
-
STL
1 stop5h 07m
Multiple Airlines
Deal found 6/25$500
This United Airlines deal was found by Cheapflights users on 6/25. 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.
Sat 8/86:00 am
STL
-
YOW
2 stops7h 17m
United Airlines
Wed 8/126:05 am
YOW
-
STL
1 stop6h 12m
United Airlines
Deal found 6/25$507
This United Airlines deal was found by Cheapflights users on 6/25. 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.
Sat 8/16:00 am
STL
-
YOW
2 stops7h 17m
United Airlines
Tue 8/46:05 am
YOW
-
STL
2 stops10h 41m
United Airlines
Deal found 6/25$513
This United Airlines deal was found by Cheapflights users on 6/24. 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.
Wed 7/228:00 am
STL
-
YOW
1 stop4h 59m
United Airlines
Wed 7/2910:44 am
YOW
-
STL
1 stop4h 39m
United Airlines
Deal found 6/24$525
This United deal was found by Cheapflights users on 6/24. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/156:00 am
STL
-
YOW
1 stop14h 35m
Multiple Airlines
Thu 7/1610:00 am
YOW
-
STL
1 stop5h 02m
Multiple Airlines
Deal found 6/24$536
This United Airlines deal was found by Cheapflights users on 6/23. 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.
Tue 9/88:50 am
STL
-
YOW
1 stop11h 45m
United Airlines
Wed 9/166:25 am
YOW
-
STL
1 stop6h 32m
United Airlines
Deal found 6/23$538
This United Airlines deal was found by Cheapflights users on 6/24. 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.
Wed 7/156:00 am
STL
-
YOW
2 stops7h 17m
United Airlines
Thu 7/163:10 pm
YOW
-
STL
1 stop9h 34m
United Airlines
Deal found 6/24$548

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 June 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$489
(Air Canada)

One-way from

$215
(United Airlines)

Popular in

December

Cheapest in

June

Average price

$204
Provider with most accurate pricing for Lambert-St Louis-Ottawa flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Ottawa flights.
Search Deals
From Lambert-St Louis to Ottawa
Search Deals
One-way flight from Lambert-St Louis to Ottawa
Search Deals
Highest demand for flights based on searches. 36% potential increase in price ($308 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($35 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals

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 June 29, 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

Price

Cheapest round-trip

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 8/12

12:59 pm-9:35 pm

1 stop7h 36m

Ottawa

Wed 8/19

6:25 am-3:38 pm

1 stop10h 13m

$497
Quickest round-trip

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 8/8

1:18 pm-11:54 pm

2 stops9h 36m

Ottawa

Wed 8/12

6:25 am-12:02 pm

1 stop6h 37m

$507

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 8/12

9:30 am-9:35 pm

1 stop11h 05m

Ottawa

Thu 8/13

6:05 am-3:38 pm

2 stops10h 33m

$507
Cheapest one-way
Quickest one-way

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 8/12

8:00 am-5:16 pm

1 stop8h 16m

$215

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 8/8

10:20 am-10:05 pm

2 stops10h 45m

$226

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 8/12

4:57 pm-9:20 pm

3 stops27h 23m

$234

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 8/8

4:57 pm-5:54 pm

3 stops23h 57m

$235

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/28

Sorted 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.
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.

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 June 29, 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.
United Airlines
7.4
Good
9,895 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Reviews

1 / 20
6.0
Good

Miz,Oct 2024

EWR - YYZ

I booked on United but it was really Air Canada. It was very confusing when I went to the airport. The ride to NY was very turbulent and shaky. The ride back was better. It would be nicer with more leg room and to get rid of the tilting the seat back thing. Fine for an hour flight but any longer would have been not great. Please put subtitles on the programs so we don;t have t use headphones if we forget them.
United Airlines
7.4
Good
9,895 reviews
United Airlines
7.4
Good
9,895 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Reviews

1 / 20
6.0
Good

Miz,Oct 2024

EWR - YYZ

I booked on United but it was really Air Canada. It was very confusing when I went to the airport. The ride to NY was very turbulent and shaky. The ride back was better. It would be nicer with more leg room and to get rid of the tilting the seat back thing. Fine for an hour flight but any longer would have been not great. Please put subtitles on the programs so we don;t have t use headphones if we forget them.
Air Canada
7.1
Good
11,271 reviews
United Airlines
7.4
Good
9,895 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Crew

8.1

Entertainment

7.1

Food

6.6

Reviews

1 / 20
6.0
Good

Miz,Oct 2024

EWR - YYZ

I booked on United but it was really Air Canada. It was very confusing when I went to the airport. The ride to NY was very turbulent and shaky. The ride back was better. It would be nicer with more leg room and to get rid of the tilting the seat back thing. Fine for an hour flight but any longer would have been not great. Please put subtitles on the programs so we don;t have t use headphones if we forget them.

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.

  • How long is the flight from St. Louis to Ottawa?

    A quick flight from St. Louis to Ottawa can take about 7h 36m. United Airlines provides one of the quickest options available for as low as $497. St. Louis and Ottawa are separated by a distance of 878 mi.

  • What are the cheapest airlines flying from St. Louis to Ottawa round-trip?

    Currently priced at $139, Air Canada will fly you from St. Louis to Ottawa and back. In addition to Air Canada, many other airlines offer competitively priced options for your trip. Check Cheapflights for deals on United Airlines for as low as $203. Air Canada is 74% cheaper than the average price of flights available within the next 90 days to this destination.

  • Can I find deals for flights from St. Louis to Ottawa that include hotel bookings?

    Yes. In addition to deals on St. Louis to Ottawa flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Ottawa?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Ottawa.

  • Can I find deals for business class flights from St. Louis to Ottawa?

    Yes. Cheapflights offers flight deals from St. Louis to Ottawa by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

Traveling to a place near Ottawa?

Book flights to Ottawa if you plan to visit one of these locations
Gatineau

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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 June 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$139Average$542FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$203Average$483FlexibilityNo cancel feeOn-time69%

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