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$319+ Cheap flights from St. Louis (STL) to Ottawa (YOW)

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 1/15. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YOW
Jan 30 — Feb 61
Fri 1/30
Fri 2/6
1 adult, Economy
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Cheap flight deals from St. Louis to Ottawa

Best flights from St. Louis to Ottawa
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 December 31, 2025.

This Booking.com deal was found by Cheapflights users on 12/30. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/154:05 pmSTL - YOW
1 stop8h 33mAir Canada
Wed 1/219:15 amYOW - STL
1 stop7h 14mAir Canada
Deal found 12/30$319
This United Airlines deal was found by Cheapflights users on 12/28. 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.
Mon 2/26:30 amSTL - YOW
2 stops9h 00mUnited Airlines
Fri 2/65:55 pmYOW - STL
1 stop7h 04mUnited Airlines
Deal found 12/28$358
This Air Canada deal was found by Cheapflights users on 12/30. 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 2/144:05 pmSTL - YOW
1 stop6h 13mAir Canada
Sat 2/2110:20 amYOW - STL
1 stop6h 09mAir Canada
Deal found 12/30$347
This United Airlines deal was found by Cheapflights users on 12/30. 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 2/149:55 amSTL - YOW
1 stop6h 12mUnited Airlines
Sat 2/212:15 pmYOW - STL
2 stops7h 50mUnited Airlines
Deal found 12/30$358
This Air Canada deal was found by Cheapflights users on 12/28. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/24:05 pmSTL - YOW
1 stop6h 03mAir Canada
Fri 2/69:15 amYOW - STL
1 stop7h 14mAir Canada
Deal found 12/28$347
This Air Canada deal was found by Cheapflights users on 12/29. 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.
Sun 1/114:05 pmSTL - YOW
1 stop8h 33mAir Canada
Sun 1/1810:20 amYOW - STL
1 stop6h 09mAir Canada
Deal found 12/29$371

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 December 31, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$312
(Kiwi.com)

Popular in

July

Cheapest in

February

Average price

$676
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
Highest demand for flights based on searches. 21% potential increase in price ($200 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($39 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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 December 31, 2025.
Use the filters below to find and compare flights from St. Louis to Ottawa that are best for you.

Fly from

St. Louis

Fly to

Ottawa

Route

Depart

Return

Price

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 1/15

4:05 pm-1:38 am

1 stop8h 33m

Ottawa

Wed 1/21

9:15 am-3:29 pm

1 stop7h 14m

$319

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 2/14

4:05 pm-11:18 pm

1 stop6h 13m

Ottawa

Sat 2/21

10:20 am-3:29 pm

1 stop6h 09m

$347

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 2/2

4:05 pm-11:08 pm

1 stop6h 03m

Ottawa

Fri 2/6

9:15 am-3:29 pm

1 stop7h 14m

$347

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 2/2

6:30 am-4:30 pm

2 stops9h 00m

Ottawa

Fri 2/6

5:55 pm-11:59 pm

1 stop7h 04m

$358

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 2/14

9:55 am-5:07 pm

1 stop6h 12m

Ottawa

Sat 2/21

2:15 pm-9:05 pm

2 stops7h 50m

$358

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sun 1/11

4:05 pm-1:38 am

1 stop8h 33m

Ottawa

Sun 1/18

10:20 am-3:29 pm

1 stop6h 09m

$371

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/30

Compare providers for flights from St. Louis to Ottawa

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 St. Louis to Ottawa in December.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on St. Louis-Ottawa flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on St. Louis-Ottawa flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Ottawa

What is the cheapest month to book a flight from St. Louis to Ottawa?

Currently, July is the cheapest month in which you can book a flight from St. Louis to Ottawa (average of $218). Flying from St. Louis to Ottawa in January is currently the most expensive (average of $601). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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 December 31, 2025.
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
9,124 reviews

Comfort

7.3

Crew

8.1

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

Reviews

1 / 20
10.0
Excellent

Michelle,Dec 2025

DEN - MKE

I liked that the plane waited 5 minutes for a family whose incoming plane was late. This was the last flight of the day to MKE. Flight attendants actually checked in throughout the flight. Although, not really friendly. Happy to see screens on seat backs again. This is my first time not flying first class in over 10 years. It was economy plus.
United Airlines
7.4
Good
9,124 reviews
United Airlines
7.4
Good
9,124 reviews

Comfort

7.3

Crew

8.1

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

Reviews

1 / 20
10.0
Excellent

Michelle,Dec 2025

DEN - MKE

I liked that the plane waited 5 minutes for a family whose incoming plane was late. This was the last flight of the day to MKE. Flight attendants actually checked in throughout the flight. Although, not really friendly. Happy to see screens on seat backs again. This is my first time not flying first class in over 10 years. It was economy plus.
Air Canada
7.1
Good
10,571 reviews
United Airlines
7.4
Good
9,124 reviews

Comfort

7.3

Crew

8.1

Overall

7.4

Entertainment

7.1

Food

6.6

Boarding

7.7

Reviews

1 / 20
10.0
Excellent

Michelle,Dec 2025

DEN - MKE

I liked that the plane waited 5 minutes for a family whose incoming plane was late. This was the last flight of the day to MKE. Flight attendants actually checked in throughout the flight. Although, not really friendly. Happy to see screens on seat backs again. This is my first time not flying first class in over 10 years. It was economy plus.

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 8h 33m. Air Canada provides one of the quickest options available for as low as $319. 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 $330, 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 $362. Air Canada is 55% 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.

  • What is the cheapest month to book a flight from St. Louis to Ottawa?

    Currently, July is the cheapest month in which you can book a flight from St. Louis to Ottawa (average of $218). Flying from St. Louis to Ottawa in January is currently the most expensive (average of $601). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Ottawa?

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

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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 December 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$330Average$879FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$362Average$824FlexibilityNo cancel feeOn-time69%

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