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$178+ Cheap flights from Ottawa (YOW) to St. Louis (STL)

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 12/27. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
Dec 13 — Dec 201
Sat 12/13
Sat 12/20
1 adult, Economy
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Cheap 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 November 13, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$300
(United Airlines)

One-way from

$178
(Air Canada)

Popular in

December

Cheapest in

November

Average price

$496
Provider with most accurate pricing for Ottawa-Lambert-St Louis flight deals.
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Provider most trusted by Cheapflights users for Ottawa-Lambert-St Louis flights.
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From Ottawa to Lambert-St Louis
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One-way flight from Ottawa to Lambert-St Louis
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Highest demand for flights based on searches. 2% potential increase in price ($13 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($11 potential savings vs. average RT price).
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Average for round-trip flights in November 2025
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Find flight deals from Ottawa to St. Louis

Cheapest flights from Ottawa to St. Louis
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 November 13, 2025.

This United Airlines deal was found by Cheapflights users on 11/11. 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.
Sat 12/275:00 amYOW - STL
1 stop11h 29mUnited Airlines
Sat 1/37:00 amSTL - YOW
1 stop5h 32mUnited Airlines
Deal found 11/11$587
This American Airlines deal was found by Cheapflights users on 11/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/276:45 amYOW - STL
2 stops10h 38mAmerican Airlines
Sat 1/38:01 pmSTL - YOW
2 stops19h 50mAmerican Airlines
Deal found 11/11$599

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 2,558,603 searches. Data last updated November 13, 2025.
Use the filters below to find and compare flights from Ottawa to St. Louis that are best for you.

Fly from

Ottawa

Fly to

St. Louis

Route

Depart

Return

Price

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 4/7

10:35 am-9:03 pm

1 stop11h 28m

Lambert-St Louis

Wed 4/8

7:45 am-1:45 pm

1 stop5h 00m

$300

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 4/7

10:35 am-9:47 pm

1 stop12h 12m

Lambert-St Louis

Wed 4/8

7:45 am-10:16 pm

2 stops13h 31m

$353

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 12/27

5:00 am-3:29 pm

1 stop11h 29m

Lambert-St Louis

Sat 1/3

7:00 am-1:32 pm

1 stop5h 32m

$587

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 12/27

6:45 am-4:23 pm

2 stops10h 38m

Lambert-St Louis

Sat 1/3

8:01 pm-4:51 pm

2 stops19h 50m

$599

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 12/27

9:15 am-3:29 pm

1 stop7h 14m

$178

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 12/28

6:00 am-11:33 pm

2 stops18h 33m

$246

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 12/27

1:20 pm-9:40 am

3 stops21h 20m

$254

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 12/27

6:45 am-4:23 pm

2 stops10h 38m

$262

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 12/28

4:35 pm-9:40 am

3 stops42h 05m

$279

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/12

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 November.
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 Ottawa-St. Louis flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ottawa-St. Louis flight deals on Cheapflights vs. eDreams >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 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 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.
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

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

Currently, November is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $350). Flying from Ottawa to St. Louis in August is currently the most expensive (average of $582). 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.

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.

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

    Departing from Ottawa to St. Louis will take you 11h 28m. The distance from Ottawa to St. Louis is about 878 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from Ottawa to St. Louis one-way?

    To fly one-way, consider booking your trip with Air Canada, which is currently one of the cheapest options available, starting at $178. United Airlines flights start at $246 while deals on American Airlines start at $262 one-way.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ottawa to St. Louis 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 Ottawa to St. Louis?

    Currently, November is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $350). Flying from Ottawa to St. Louis in August is currently the most expensive (average of $582). 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
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

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