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Cheap flights from Ottawa to St. Louis from C$ 872

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 3/8. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
4 May — 11 May1
1 adult

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 29 April 2025.

Round-trip from

C$ 872

Popular in

August

Cheapest in

September

Average price

C$ 977
United Airlines
  • United Airlines
  • 3/8-7/8
  • 2 total stops
  • 14h 57m total
  • Ottawa to St. Louis
Search Deals
Highest demand for flights based on searches. 1% potential increase in price (C$ 14 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease (C$ 19 potential savings vs. average RT price).
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Average for round-trip flights in April 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 29 April 2025.

Sun 3/85:50 p.m.YOW - STL
1 stop6h 53mUnited Airlines
Thu 7/85:00 a.m.STL - YOW
1 stop8h 04mUnited Airlines
Deal found 27/4C$ 872
Wed 24/126:52 a.m.YOW - STL
1 stop6h 28mMultiple Airlines
Sat 3/15:00 a.m.STL - YOW
2 stops9h 17mMultiple Airlines
Deal found 28/4C$ 880

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 629,999 searches. Data last updated 29 April 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

Sun 3/8

5:50 p.m.-11:43 p.m.

1 stop6h 53m

Lambert-St Louis

Thu 7/8

5:00 a.m.-2:04 p.m.

1 stop8h 04m

C$ 872

Flights are sorted by cheapest round-trip flights first.

Deals found on 27/4

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, January is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of C$ 365). Flying from Ottawa to St. Louis in September is currently the most expensive (average of C$ 491). 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 St. Louis by month

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

In terms of precipitation, rainfall in St. Louis ranges from 56.0 - 119.0 mm per month. May is typically the wettest month, when rainfall can reach 119.0 mm. February is typically the driest time to visit St. Louis when rainfall is around 56.0 mm.

Temperature in St. Louis by month

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

If weather is an important factor for your trip to St. Louis, 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 27.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 0.0 C).

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated 29 April 2025.
United Airlines
7.4
Good
8,696 reviews
Check prices

Crew

8.1

Food

6.6

Boarding

7.7

Comfort

7.3

Entertainment

7.1

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.
United Airlines
7.4
Good
8,696 reviews
United Airlines
7.4
Good
8,696 reviews
Check prices

Crew

8.1

Food

6.6

Boarding

7.7

Comfort

7.3

Entertainment

7.1

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Apr 2025

TPE - SFO

The boarding experience was okay. The dietary food choices were limited, the midway snacks were hard and dry. The seat was uncomfortable - stiff seat cushion, seat back kept springing back to the upright position, narrow seat width. Love the app and the ability to track my luggage. Flight crew was efficient.

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.

  • What is the cheapest airline to fly from Ottawa to St. Louis round-trip?

    United Airlines, at C$ 872, was found to be the cheapest airline from Ottawa to St. Louis.. United Airlines is currently priced 4% below the average price you’ll pay for this route.

  • 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, January is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of C$ 365). Flying from Ottawa to St. Louis in September is currently the most expensive (average of C$ 491). 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

Travelling to a place near Ottawa?

Book flights to Ottawa if you plan to visit one of these locations
Chesterfield
St. Peters

Browse thousands of different options on Cheapflights for your next trip

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Top airline flying from Ottawa to St. Louis

Discover the top airline that operate flights from Ottawa to St. Louis. 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 629,999 searches. Data last updated 29 April 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 762AverageC$ 886FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

Fly with Cheapflights

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How does Cheapflights help users find flights from Ottawa to St. Louis?

When you search for this flight from Ottawa to St. Louis, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Ottawa to St. Louis?

Cheapflights helps you find that perfect flight to St. Louis from Ottawa by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Ottawa to St. Louis with no change fees?

Users can book flights with no change fees policies with our dedicated filters. Book flights from Ottawa to St. Louis flexibly with Cheapflights today.

Can Cheapflights notify me if prices for flights from Ottawa to St. Louis become cheaper?

Yes! Start tracking prices for Ottawa to St. Louis flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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