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Cheap flights from Ottawa to St. Louis from C$ 269

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ottawa to St. Louis departing on 22/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult

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Find the cheapest flights from Ottawa to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
5:20 p.m. - 9:08 p.m.
YOW
-
STL
4h 48m
1 stop
United Airlines Logo
7:45 a.m. - 1:59 p.m.
STL
-
YOW
5h 14m
1 stop
C$ 434United Airlines
Thu, 9 Apr - Sat, 11 Apr
United Airlines Logo
5:11 p.m. - 9:58 p.m.
YOW
-
STL
5h 47m
1 stop
United Airlines Logo
10:00 a.m. - 5:07 p.m.
STL
-
YOW
6h 07m
1 stop
C$ 436United Airlines
Fri, 27 Mar - Mon, 30 Mar
United Airlines Logo
6:00 a.m. - 9:08 p.m.
YOW
-
STL
16h 08m
3 stops
United Airlines Logo
7:45 a.m. - 1:59 p.m.
STL
-
YOW
5h 14m
1 stop
C$ 448United Airlines
Thu, 9 Apr - Sat, 11 Apr
Air Canada Logo
7:15 a.m. - 3:29 p.m.
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
4:05 p.m. - 11:18 p.m.
STL
-
YOW
6h 13m
1 stop
C$ 501Air Canada
Sun, 1 Mar - Wed, 4 Mar
Air Canada Logo
7:15 a.m. - 3:29 p.m.
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
4:05 p.m. - 11:18 p.m.
STL
-
YOW
6h 13m
1 stop
C$ 502Air Canada
Sun, 1 Mar - Wed, 4 Mar
United Airlines Logo
5:11 p.m. - 9:23 p.m.
YOW
-
STL
5h 12m
1 stop
United Airlines Logo
6:35 p.m. - 2:27 p.m.
STL
-
YOW
18h 52m
2 stops
C$ 509United Airlines
Fri, 27 Mar - Mon, 30 Mar
Air Canada Logo
9:15 a.m. - 3:24 p.m.
YOW
-
STL
7h 09m
1 stop
Air Canada Logo
7:45 a.m. - 7:34 p.m.
STL
-
YOW
10h 49m
2 stops
C$ 528Air Canada
Thu, 9 Apr - Sat, 11 Apr
Air Canada Logo
7:15 a.m. - 3:29 p.m.
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
4:05 p.m. - 1:38 a.m.
STL
-
YOW
8h 33m
1 stop
C$ 553Air Canada
Sun, 1 Mar - Wed, 4 Mar
Air Canada Logo
7:15 a.m. - 3:29 p.m.
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
7:41 a.m. - 4:23 p.m.
STL
-
YOW
7h 42m
2 stops
C$ 568Air Canada
Sun, 1 Mar - Wed, 4 Mar
Air Canada Logo
7:15 a.m. - 3:29 p.m.
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
7:41 a.m. - 4:23 p.m.
STL
-
YOW
7h 42m
2 stops
C$ 569Air Canada
Sun, 1 Mar - Wed, 4 Mar

Air Canada flights from Ottawa to St. Louis

Our best Air Canada deals on Ottawa to St. Louis flight tickets
Air Canada
1 Mar
YOW7:15 a.m.Ottawa
9h 14m
1 stop
STL3:29 p.m.Lambert-St Louis
4 Mar
STL4:05 p.m.Lambert-St Louis
6h 13m
1 stop
YOW11:18 p.m.Ottawa
C$ 501
Air Canada
9 Apr
YOW9:15 a.m.Ottawa
7h 09m
1 stop
STL3:24 p.m.Lambert-St Louis
11 Apr
STL7:45 a.m.Lambert-St Louis
10h 49m
2 stops
YOW7:34 p.m.Ottawa
C$ 528
Air Canada
1 Mar
YOW7:15 a.m.Ottawa
9h 14m
1 stop
STL3:29 p.m.Lambert-St Louis
4 Mar
STL4:05 p.m.Lambert-St Louis
8h 33m
1 stop
YOW1:38 a.m.Ottawa
C$ 553

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
9 Apr
YOW5:20 p.m.Ottawa
4h 48m
1 stop
STL9:08 p.m.Lambert-St Louis
11 Apr
STL7:45 a.m.Lambert-St Louis
5h 14m
1 stop
YOW1:59 p.m.Ottawa
C$ 434
United Airlines
27 Mar
YOW5:11 p.m.Ottawa
5h 47m
1 stop
STL9:58 p.m.Lambert-St Louis
30 Mar
STL10:00 a.m.Lambert-St Louis
6h 07m
1 stop
YOW5:07 p.m.Ottawa
C$ 436
United Airlines
9 Apr
YOW6:00 a.m.Ottawa
16h 08m
3 stops
STL9:08 p.m.Lambert-St Louis
11 Apr
STL7:45 a.m.Lambert-St Louis
5h 14m
1 stop
YOW1:59 p.m.Ottawa
C$ 448

momondo 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, momondo users made 96,600 searches. Data last updated 5 February 2026.
Use the filters below to find and compare flights from Ottawa to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 9/4

5:20 p.m.-9:08 p.m.

1 stop4h 48m

Lambert-St Louis

Sat 11/4

7:45 a.m.-1:59 p.m.

1 stop5h 14m

C$ 434

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 27/3

5:11 p.m.-9:58 p.m.

1 stop5h 47m

Lambert-St Louis

Mon 30/3

10:00 a.m.-5:07 p.m.

1 stop6h 07m

C$ 436

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 9/4

6:00 a.m.-9:08 p.m.

3 stops16h 08m

Lambert-St Louis

Sat 11/4

7:45 a.m.-1:59 p.m.

1 stop5h 14m

C$ 448

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

4:05 p.m.-11:18 p.m.

1 stop6h 13m

C$ 501

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

4:05 p.m.-11:18 p.m.

1 stop6h 13m

C$ 502

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 27/3

5:11 p.m.-9:23 p.m.

1 stop5h 12m

Lambert-St Louis

Mon 30/3

6:35 p.m.-2:27 p.m.

2 stops18h 52m

C$ 509

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 9/4

9:15 a.m.-3:24 p.m.

1 stop7h 09m

Lambert-St Louis

Sat 11/4

7:45 a.m.-7:34 p.m.

2 stops10h 49m

C$ 528

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

4:05 p.m.-1:38 a.m.

1 stop8h 33m

C$ 553

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

7:41 a.m.-4:23 p.m.

2 stops7h 42m

C$ 568

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/3

7:15 a.m.-3:29 p.m.

1 stop9h 14m

Lambert-St Louis

Wed 4/3

7:41 a.m.-4:23 p.m.

2 stops7h 42m

C$ 569

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 19 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Ottawa to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to St. Louis?

The month of January is, on average, the cheapest month to fly to St. Louis from Ottawa, with most prices found around C$ 554. If you don’t want to visit St. Louis in January, then you should wait until November to fly from Ottawa, when ticket prices are also cheap, with an average price of C$ 677.

Can stopping save me money on Ottawa to St. Louis flights?

You could potentially save up to 35% on your flight if you consider stops on a Ottawa to St. Louis flight.

When to book flights from Ottawa to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Ottawa to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ottawa to St. Louis (YOW to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ottawa to St. Louis

Fastest flight time

4h 48m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 4h 48m
There are no direct flights from Ottawa to St. Louis. There are no popular flight routes from Ottawa to St. Louis.
Search flight deals

  • How far is Ottawa to Lambert-St Louis by plane?

    A flight from Ottawa to Lambert-St Louis will travel around 1411.6 km. 4h 48m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Ottawa Airport to Lambert-St Louis Airport?

    Prices for flights from Ottawa Airport to Lambert-St Louis Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Ottawa Airport to Lambert-St Louis Airport?

  • How old do you have to be to fly from Ottawa Airport to Lambert-St Louis Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ottawa Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Ottawa to St. Louis?

Best airlines flying from Ottawa to St. Louis

Compare and see reviews for airlines that fly from Ottawa to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
United AirlinesPriceFrom C$ 474Free CancellationRating
7.4
9,240 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 484Free CancellationRating
7.1
10,694 reviews
Search Air Canada flights

Travelling to a place near St. Louis?

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

Why use momondo?

Why should I use momondo to find a flight deal from Ottawa to St. Louis?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Ottawa to St. Louis for you.

Can I find flights from Ottawa to St. Louis with flexible booking policies on momondo?

All flight searches from Ottawa to St. Louis on momondo can be filtered to show those which offer flexible booking policies.

How can momondo help me find flights from Ottawa to St. Louis?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ottawa to St. Louis.

I’m not ready to book a flight from Ottawa to St. Louis right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to St. Louis from Ottawa. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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