HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ottawa

$438+ 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 4/7. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YOW
Feb 27 — Mar 61
Thu 2/27
Thu 3/6
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

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
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 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 February 22, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$438
(Kiwi.com)
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

Find 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 February 22, 2025.

This Kiwi.com deal was found by Cheapflights users on 2/21. 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.
Mon 4/76:38 pmSTL - YOW
2 stops12h 42mMultiple Airlines
Mon 4/149:25 amYOW - STL
1 stop15h 21mMultiple Airlines
Deal found 2/21$438
This United Airlines deal was found by Cheapflights users on 2/21. 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 4/79:39 amSTL - YOW
1 stop10h 56mUnited Airlines
Mon 4/146:33 amYOW - STL
1 stop10h 14mUnited Airlines
Deal found 2/21$777
This Air Canada deal was found by Cheapflights users on 2/21. 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 7/31:30 pmSTL - YOW
1 stop5h 45mAir Canada
Mon 7/710:00 amYOW - STL
1 stop6h 16mAir Canada
Deal found 2/21$805
This Delta deal was found by Cheapflights users on 2/20. 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.
Fri 3/2110:30 amSTL - YOW
2 stops12h 39mDelta
Fri 3/285:55 amYOW - STL
2 stops11h 53mDelta
Deal found 2/20$813

Find flights from St. Louis to Ottawa within your budget

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 February 22, 2025.

Fly from

St. Louis

Fly to

Ottawa

Route

Depart

Return

Price

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 4/7

6:38 pm-8:20 am

2 stops12h 42m

Ottawa

Mon 4/14

9:25 am-11:46 pm

1 stop15h 21m

$438

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 4/7

9:39 am-9:35 pm

1 stop10h 56m

Ottawa

Mon 4/14

6:33 am-3:47 pm

1 stop10h 14m

$777

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 7/3

1:30 pm-8:15 pm

1 stop5h 45m

Ottawa

Mon 7/7

10:00 am-3:16 pm

1 stop6h 16m

$805

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Fri 3/21

10:30 am-12:09 am

2 stops12h 39m

Ottawa

Fri 3/28

5:55 am-4:48 pm

2 stops11h 53m

$813

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/21

  • 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.

Travel insights for flights from St. Louis to Ottawa

Get recent, data-driven insights about flights from St. Louis to Ottawa including ideal travel times, pricing trends, and more.

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

Currently, January is the cheapest month in which you can book a flight from St. Louis to Ottawa (average of $294). Flying from St. Louis to Ottawa in May is currently the most expensive (average of $474). 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.

Rainfall in Ottawa by month

Plan your trip to Ottawa by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ottawa ranges from 2.0 - 3.7 inches per month. June is typically the wettest month, when rainfall can reach 3.7 in. February is typically the driest time to visit Ottawa when rainfall is around 2.0 in.

Temperature in Ottawa by month

Plan your trip to Ottawa by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ottawa, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 69.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 14.0 F).

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 February 22, 2025.
Delta
8.0
Very good
8,203 reviews

Entertainment

7.9

Crew

8.5

Comfort

8.0

Overall

8.0

Boarding

8.2

Food

7.3

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Delta
8.0
Very good
8,203 reviews
Delta
8.0
Very good
8,203 reviews

Entertainment

7.9

Crew

8.5

Comfort

8.0

Overall

8.0

Boarding

8.2

Food

7.3

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

United Airlines
7.4
Good
8,754 reviews
Delta
8.0
Very good
8,203 reviews

Entertainment

7.9

Crew

8.5

Comfort

8.0

Overall

8.0

Boarding

8.2

Food

7.3

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Air Canada
7.0
Good
8,757 reviews
Delta
8.0
Very good
8,203 reviews

Entertainment

7.9

Crew

8.5

Comfort

8.0

Overall

8.0

Boarding

8.2

Food

7.3

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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.

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

    Currently priced at $777, United Airlines will fly you from St. Louis to Ottawa and back. In addition to United Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Air Canada and Delta - these airlines can fly you to your destination from $805 and $813, respectively.

  • 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, January is the cheapest month in which you can book a flight from St. Louis to Ottawa (average of $294). Flying from St. Louis to Ottawa in May is currently the most expensive (average of $474). 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 St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Gatineau
Brockville
Pembroke
Petawawa

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 February 22, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$329Average$764FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$379Average$816FlexibilityNo cancel feeOn-time69%
100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.