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St. Louis

$227+ 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 8/16. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
jul. 8 — jul. 151
mar. 7/8
mar. 7/15
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 julio 3, 2025.

Round-trip from

$393
(Kiwi.com)

One-way from

$227
(Mytrip)

Popular in

August

Cheapest in

September

Average price

$673
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. 1% potential increase in price ($10 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in July 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 julio 3, 2025.

This Kiwi.com deal was found by Cheapflights users on 7/1. 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.
mar. 7/294:25 pmYOW - STL
1 stop19h 04mMultiple Airlines
mar. 8/55:26 pmSTL - YOW
1 stop22h 49mMultiple Airlines
Deal found 7/1$393
This United Airlines deal was found by Cheapflights users on 7/2. 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.
sáb. 8/166:33 amYOW - STL
1 stop10h 14mUnited Airlines
sáb. 8/239:17 amSTL - YOW
1 stop6h 49mUnited Airlines
Deal found 7/2$552
This Air Canada deal was found by Cheapflights users on 7/1. 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.
jue. 7/176:33 amYOW - STL
1 stop5h 07mAir Canada
jue. 7/174:00 pmSTL - YOW
1 stop7h 20mAir Canada
Deal found 7/1$647
This FlightHub deal was found by Cheapflights users on 7/1. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 7/175:55 amYOW - STL
2 stops8h 26mWestJet
jue. 7/173:41 pmSTL - YOW
2 stops7h 41mWestJet
Deal found 7/1$860

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 julio 3, 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

mar. 7/29

4:25 pm-10:29 am

1 stop19h 04m

Lambert-St Louis

mar. 8/5

5:26 pm-5:15 pm

1 stop22h 49m

$393

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 8/16

6:33 am-3:47 pm

1 stop10h 14m

Lambert-St Louis

sáb. 8/23

9:17 am-5:06 pm

1 stop6h 49m

$552

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

jue. 7/17

6:33 am-10:40 am

1 stop5h 07m

Lambert-St Louis

jue. 7/17

4:00 pm-12:20 am

1 stop7h 20m

$647

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

jue. 7/17

5:55 am-1:21 pm

2 stops8h 26m

Lambert-St Louis

jue. 7/17

3:41 pm-12:22 am

2 stops7h 41m

$860

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 8/16

7:00 am-1:32 pm

3 stops31h 32m

$227

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 11/15

9:15 am-3:29 pm

1 stop7h 14m

$280

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 8/16

5:15 am-10:45 pm

2 stops18h 30m

$328

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/1

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, August is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $311). Flying from Ottawa to St. Louis in March is currently the most expensive (average of $356). 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.

How much does it cost to fly round-trip from Ottawa to St. Louis?

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 julio 3, 2025.
Read through reviews of airlines operating flights from Ottawa to St. Louis, such as United Airlines, WestJet, and Air Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,845 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Entertainment

7.0

Crew

8.1

Food

6.6

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
8,845 reviews
United Airlines
7.4
Good
8,845 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Entertainment

7.0

Crew

8.1

Food

6.6

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
2,917 reviews
United Airlines
7.4
Good
8,845 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Entertainment

7.0

Crew

8.1

Food

6.6

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
7.1
Good
9,678 reviews
United Airlines
7.4
Good
8,845 reviews

Comfort

7.3

Boarding

7.7

Overall

7.4

Entertainment

7.0

Crew

8.1

Food

6.6

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?

    Our cheapest airline available from Ottawa to St. Louis is United Airlines. Our recent data shows that you can find tickets from as low as $552 on this airline. Additional options worth looking into are Air Canada and WestJet, starting at $647 and $860 round-trip. You may be able to fly from Ottawa to St. Louis for 15% less than the average price by searching for these airlines.

  • 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, August is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $311). Flying from Ottawa to St. Louis in March is currently the most expensive (average of $356). 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?

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