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Cheap flights from Ottawa to St. Louis from C$ 374

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 20/6. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
20 Apr — 27 Apr1
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 15 April 2025.

Round-trip from

C$ 798

One-way from

C$ 374

Popular in

August

Cheapest in

September

Average price

C$ 980
Air Canada
  • Air Canada
  • 21/6-22/6
  • 2 total stops
  • 14h 37m total
  • Ottawa to St. Louis
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20/6
  • 20/6
  • 1 total stop
  • 8h 28m total
  • Ottawa to St. Louis
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Highest demand for flights based on searches. 0% potential increase in price (C$ 11 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 15 April 2025.

Sat 19/44:20 p.m.YOW - STL
1 stop8h 26mMultiple Airlines
Mon 5/59:55 p.m.STL - YOW
2 stops22h 06mMultiple Airlines
Deal found 15/4C$ 574
Sat 21/62:25 p.m.YOW - STL
1 stop6h 33mAir Canada
Sun 22/65:00 a.m.STL - YOW
1 stop8h 04mAir Canada
Deal found 14/4C$ 798
Sat 21/65:15 a.m.YOW - STL
2 stops11h 15mUnited Airlines
Sun 22/68:10 a.m.STL - YOW
1 stop4h 54mUnited Airlines
Deal found 14/4C$ 811
Sat 21/65:55 a.m.YOW - STL
2 stops28h 42mWestJet
Sun 22/61:30 p.m.STL - YOW
2 stops9h 52mWestJet
Deal found 14/4C$ 830

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 15 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

Sat 21/6

2:25 p.m.-7:58 p.m.

1 stop6h 33m

Lambert-St Louis

Sun 22/6

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

1 stop8h 04m

C$ 798

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 21/6

5:15 a.m.-3:30 p.m.

2 stops11h 15m

Lambert-St Louis

Sun 22/6

8:10 a.m.-2:04 p.m.

1 stop4h 54m

C$ 811

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sat 21/6

5:55 a.m.-9:37 a.m.

2 stops28h 42m

Lambert-St Louis

Sun 22/6

1:30 p.m.-12:22 a.m.

2 stops9h 52m

C$ 830

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 20/6

4:25 p.m.-11:53 p.m.

1 stop8h 28m

C$ 374

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 20/6

7:29 p.m.-10:45 a.m.

2 stops16h 16m

C$ 484

Flights are sorted by cheapest round-trip flights first.

Deals found on 13/4

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 15 April 2025.
United Airlines
7.4
Good
8,658 reviews
Check prices

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Comfort

7.3

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
8,658 reviews
United Airlines
7.4
Good
8,658 reviews
Check prices

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Comfort

7.3

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.
WestJet
7.2
Good
2,805 reviews
United Airlines
7.4
Good
8,658 reviews
Check prices

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Comfort

7.3

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.
Air Canada
7.0
Good
9,127 reviews
United Airlines
7.4
Good
8,658 reviews
Check prices

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Comfort

7.3

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

    Air Canada, at C$ 798, was found to be the cheapest airline from Ottawa to St. Louis.Alternate airlines to your destination round-trip include United Airlines and WestJet. Air Canada is currently priced 12% 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 15 April 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapestC$ 764AverageC$ 882FlexibilityNo cancel feeOn-time67%
Search Air Canada flights

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

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

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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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