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Cheap flights from Ottawa to St. Louis from C$ 296

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 6/10. 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
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

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
11:00 a.m. - 3:38 p.m.
YOW
-
STL
5h 38m
1 stop
United Airlines Logo
9:23 a.m. - 5:14 p.m.
STL
-
YOW
6h 51m
1 stop
C$ 525United Airlines
Tue, 27 Oct - Wed, 28 Oct
United Airlines Logo
6:00 p.m. - 11:25 p.m.
YOW
-
STL
6h 25m
1 stop
United Airlines Logo
10:23 a.m. - 5:14 p.m.
STL
-
YOW
5h 51m
1 stop
C$ 526United Airlines
Mon, 14 Dec - Tue, 15 Dec
United Airlines Logo
6:25 a.m. - 12:11 p.m.
YOW
-
STL
6h 46m
1 stop
United Airlines Logo
6:50 a.m. - 1:59 p.m.
STL
-
YOW
6h 09m
1 stop
C$ 546United Airlines
Wed, 1 Jul - Sun, 5 Jul
United Airlines Logo
5:50 p.m. - 11:44 p.m.
YOW
-
STL
6h 54m
1 stop
United Airlines Logo
1:13 p.m. - 9:35 p.m.
STL
-
YOW
7h 22m
1 stop
C$ 547United Airlines
Mon, 20 Jul - Fri, 24 Jul
United Airlines Logo
3:10 p.m. - 11:44 p.m.
YOW
-
STL
9h 34m
1 stop
United Airlines Logo
11:25 a.m. - 5:07 p.m.
STL
-
YOW
4h 42m
1 stop
C$ 551United Airlines
Fri, 3 Jul - Tue, 7 Jul
Air Canada Logo
9:55 a.m. - 3:38 p.m.
YOW
-
STL
6h 43m
2 stops
Air Canada Logo
8:00 a.m. - 7:51 p.m.
STL
-
YOW
10h 51m
2 stops
C$ 609Air Canada
Tue, 27 Oct - Wed, 28 Oct
Air Canada Logo
9:55 a.m. - 3:38 p.m.
YOW
-
STL
6h 43m
2 stops
Air Canada Logo
10:23 a.m. - 9:56 p.m.
STL
-
YOW
10h 33m
2 stops
C$ 610Air Canada
Tue, 27 Oct - Wed, 28 Oct
United Airlines Logo
6:00 p.m. - 11:25 p.m.
YOW
-
STL
6h 25m
1 stop
United Airlines Logo
10:23 a.m. - 9:56 p.m.
STL
-
YOW
10h 33m
2 stops
C$ 620United Airlines
Mon, 14 Dec - Tue, 15 Dec
United Airlines Logo
6:00 a.m. - 3:46 p.m.
YOW
-
STL
10h 46m
2 stops
United Airlines Logo
6:50 a.m. - 1:59 p.m.
STL
-
YOW
6h 09m
1 stop
C$ 630United Airlines
Wed, 1 Jul - Sun, 5 Jul
Air Canada Logo
5:20 p.m. - 11:29 p.m.
YOW
-
STL
7h 09m
2 stops
Air Canada Logo
12:10 p.m. - 7:45 p.m.
STL
-
YOW
6h 35m
1 stop
C$ 647Air Canada
Fri, 3 Jul - Tue, 7 Jul

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Delta flights from Ottawa to St. Louis

Our best Delta deals on Ottawa to St. Louis flight tickets
Delta
14 Dec
YOW5:40 a.m.Ottawa
8h 40m
2 stops
STL1:20 p.m.Lambert-St Louis
15 Dec
STL1:30 p.m.Lambert-St Louis
10h 12m
2 stops
YOW12:42 a.m.Ottawa
C$ 685
Delta
14 Dec
YOW5:40 a.m.Ottawa
8h 40m
2 stops
STL1:20 p.m.Lambert-St Louis
15 Dec
STL1:30 p.m.Lambert-St Louis
10h 12m
2 stops
YOW12:42 a.m.Ottawa
C$ 715
Delta
3 Jul
YOW6:55 a.m.Ottawa
16h 23m
2 stops
STL10:18 p.m.Lambert-St Louis
7 Jul
STL7:08 a.m.Lambert-St Louis
16h 12m
2 stops
YOW12:20 a.m.Ottawa
C$ 807

American Airlines flights from Ottawa to St. Louis

Our best American Airlines deals on Ottawa to St. Louis flight tickets
American Airlines
28 Jul
YOW8:40 a.m.Ottawa
16h 36m
2 stops
STL12:16 a.m.Lambert-St Louis
4 Aug
STL6:55 a.m.Lambert-St Louis
13h 40m
3 stops
YOW9:35 p.m.Ottawa
C$ 1,051
American Airlines
30 Jul
YOW7:00 a.m.Ottawa
11h 21m
3 stops
STL5:21 p.m.Lambert-St Louis
6 Aug
STL8:07 p.m.Lambert-St Louis
17h 48m
2 stops
YOW2:55 p.m.Ottawa
C$ 1,178
American Airlines
31 Jul
YOW7:00 a.m.Ottawa
11h 02m
3 stops
STL5:02 p.m.Lambert-St Louis
7 Aug
STL6:00 a.m.Lambert-St Louis
7h 55m
2 stops
YOW2:55 p.m.Ottawa
C$ 1,208

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 18 June 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

Cheapest round-trip

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 27/10

11:00 a.m.-3:38 p.m.

1 stop5h 38m

Lambert-St Louis

Wed 28/10

9:23 a.m.-5:14 p.m.

1 stop6h 51m

C$ 525
Quickest round-trip

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 14/12

6:00 p.m.-11:25 p.m.

1 stop6h 25m

Lambert-St Louis

Tue 15/12

10:23 a.m.-5:14 p.m.

1 stop5h 51m

C$ 526

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 1/7

6:25 a.m.-12:11 p.m.

1 stop6h 46m

Lambert-St Louis

Sun 5/7

6:50 a.m.-1:59 p.m.

1 stop6h 09m

C$ 546

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 20/7

5:50 p.m.-11:44 p.m.

1 stop6h 54m

Lambert-St Louis

Fri 24/7

1:13 p.m.-9:35 p.m.

1 stop7h 22m

C$ 547

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 3/7

3:10 p.m.-11:44 p.m.

1 stop9h 34m

Lambert-St Louis

Tue 7/7

11:25 a.m.-5:07 p.m.

1 stop4h 42m

C$ 551

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 27/10

9:55 a.m.-3:38 p.m.

2 stops6h 43m

Lambert-St Louis

Wed 28/10

8:00 a.m.-7:51 p.m.

2 stops10h 51m

C$ 609

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 27/10

9:55 a.m.-3:38 p.m.

2 stops6h 43m

Lambert-St Louis

Wed 28/10

10:23 a.m.-9:56 p.m.

2 stops10h 33m

C$ 610

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 14/12

6:00 p.m.-11:25 p.m.

1 stop6h 25m

Lambert-St Louis

Tue 15/12

10:23 a.m.-9:56 p.m.

2 stops10h 33m

C$ 620

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 1/7

6:00 a.m.-3:46 p.m.

2 stops10h 46m

Lambert-St Louis

Sun 5/7

6:50 a.m.-1:59 p.m.

1 stop6h 09m

C$ 630

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 3/7

5:20 p.m.-11:29 p.m.

2 stops7h 09m

Lambert-St Louis

Tue 7/7

12:10 p.m.-7:45 p.m.

1 stop6h 35m

C$ 647

Flights are sorted by cheapest round-trip flights 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 typical price of a round-trip flight between Ottawa and St. Louis?

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

The month of February is, on average, the cheapest month to fly to St. Louis from Ottawa, with most prices found around C$ 0. If you don’t want to visit St. Louis in February, then you should wait until May to fly from Ottawa, when ticket prices are also cheap, with an average price of C$ 412.

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 39m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 4h 39m
There are no direct flights from Ottawa to St. Louis. There are no popular flight routes from Ottawa to St. Louis.
Search flight deals

Frequently asked questions about flying from Ottawa to St. Louis

  • 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 39m 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$ 404Free CancellationRating
7.4
9,859 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 413Free CancellationRating
7.1
11,212 reviews
Search Air Canada flights

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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