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Cheap flights from Ottawa to St. Louis from C$ 364

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 15/9. 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

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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.
Multiple Airlines Logo
7:00 a.m. - 7:39 p.m.YOW  Ottawa-STL Lambert-St Louis
13h 39m1 stop Orlando
Multiple Airlines Logo
10:35 a.m. - 4:44 p.m.STL  Lambert-St Louis-YOW Ottawa
29h 09m2 stops Atlanta Hartsfield-Jackson Orlando
C$ 605Multiple Airlines
Fri, 23 Oct - Mon, 26 Oct
Air Canada Logo
2:35 p.m. - 6:42 p.m.YOW  Ottawa-STL Lambert-St Louis
5h 07m1 stop Montreal Pierre Elliott Trudeau Intl
Air Canada Logo
12:10 p.m. - 7:45 p.m.STL  Lambert-St Louis-YOW Ottawa
6h 35m1 stop Montreal Pierre Elliott Trudeau Intl
C$ 632Air Canada
Mon, 31 Aug - Wed, 9 Sep
Air Canada Logo
10:00 a.m. - 2:00 p.m.YOW  Ottawa-STL Lambert-St Louis
5h 00m1 stop Toronto Pearson Intl
Air Canada Logo
4:05 p.m. - 9:50 p.m.STL  Lambert-St Louis-YOW Ottawa
4h 45m1 stop Toronto Pearson Intl
C$ 640Air Canada
Sat, 24 Oct - Mon, 26 Oct
United Airlines Logo
6:15 a.m. - 9:13 p.m.YOW  Ottawa-STL Lambert-St Louis
15h 58m1 stop Chicago O'Hare Intl
United Airlines Logo
6:30 a.m. - 1:26 p.m.STL  Lambert-St Louis-YOW Ottawa
5h 56m1 stop Newark
C$ 660United Airlines
Tue, 1 Dec - Wed, 2 Dec
United Airlines Logo
6:15 a.m. - 9:13 p.m.YOW  Ottawa-STL Lambert-St Louis
15h 58m1 stop Chicago O'Hare Intl
United Airlines Logo
6:30 a.m. - 1:26 p.m.STL  Lambert-St Louis-YOW Ottawa
5h 56m1 stop Newark
C$ 661United Airlines
Tue, 1 Dec - Wed, 2 Dec
Multiple Airlines Logo
7:00 a.m. - 7:39 p.m.YOW  Ottawa-STL Lambert-St Louis
13h 39m1 stop Orlando
Multiple Airlines Logo
8:34 p.m. - 4:44 p.m.STL  Lambert-St Louis-YOW Ottawa
19h 10m1 stop Orlando
C$ 668Multiple Airlines
Fri, 23 Oct - Mon, 26 Oct
United Airlines Logo
4:36 p.m. - 11:09 p.m.YOW  Ottawa-STL Lambert-St Louis
7h 33m1 stop Chicago O'Hare Intl
United Airlines Logo
7:33 a.m. - 9:56 p.m.STL  Lambert-St Louis-YOW Ottawa
13h 23m2 stops Chicago O'Hare Intl Newark
C$ 688United Airlines
Tue, 1 Dec - Wed, 2 Dec
Air Canada Logo
9:55 a.m. - 3:41 p.m.YOW  Ottawa-STL Lambert-St Louis
6h 46m2 stops Toronto Island Chicago O'Hare Intl
Air Canada Logo
7:33 a.m. - 2:09 p.m.STL  Lambert-St Louis-YOW Ottawa
5h 36m1 stop Chicago O'Hare Intl
C$ 744Air Canada
Tue, 1 Dec - Wed, 2 Dec
Multiple Airlines Logo
6:00 a.m. - 3:38 p.m.YOW  Ottawa-STL Lambert-St Louis
10h 38m3 stops Washington, D.C. Dulles Intl Indianapolis Chicago O'Hare Intl
Multiple Airlines Logo
10:53 a.m. - 7:52 p.m.STL  Lambert-St Louis-YOW Ottawa
7h 59m2 stops Chicago O'Hare Intl Toronto Island
C$ 827Multiple Airlines
Mon, 31 Aug - Wed, 9 Sep
American Airlines Logo
7:00 a.m. - 9:13 p.m.YOW  Ottawa-STL Lambert-St Louis
15h 13m3 stops Toronto Pearson Intl Washington, D.C. Reagan-National Chicago O'Hare Intl
American Airlines Logo
7:29 a.m. - 5:58 p.m.STL  Lambert-St Louis-YOW Ottawa
9h 29m2 stops Chicago O'Hare Intl Toronto Pearson Intl
C$ 1,211American Airlines
Sat, 24 Oct - Mon, 26 Oct

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United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
1 Dec
YOW6:15 a.m.Ottawa
15h 58m
1 stop
STL9:13 p.m.Lambert-St Louis
2 Dec
STL6:30 a.m.Lambert-St Louis
5h 56m
1 stop
YOW1:26 p.m.Ottawa
C$ 660
United Airlines
1 Dec
YOW6:15 a.m.Ottawa
15h 58m
1 stop
STL9:13 p.m.Lambert-St Louis
2 Dec
STL6:30 a.m.Lambert-St Louis
5h 56m
1 stop
YOW1:26 p.m.Ottawa
C$ 661
United Airlines
1 Dec
YOW4:36 p.m.Ottawa
7h 33m
1 stop
STL11:09 p.m.Lambert-St Louis
2 Dec
STL7:33 a.m.Lambert-St Louis
13h 23m
2 stops
YOW9:56 p.m.Ottawa
C$ 688

Air Canada flights from Ottawa to St. Louis

Our best Air Canada deals on Ottawa to St. Louis flight tickets
Air Canada
31 Aug
YOW2:35 p.m.Ottawa
5h 07m
1 stop
STL6:42 p.m.Lambert-St Louis
9 Sep
STL12:10 p.m.Lambert-St Louis
6h 35m
1 stop
YOW7:45 p.m.Ottawa
C$ 632
Air Canada
24 Oct
YOW10:00 a.m.Ottawa
5h 00m
1 stop
STL2:00 p.m.Lambert-St Louis
26 Oct
STL4:05 p.m.Lambert-St Louis
4h 45m
1 stop
YOW9:50 p.m.Ottawa
C$ 640
Air Canada
1 Dec
YOW9:55 a.m.Ottawa
6h 46m
2 stops
STL3:41 p.m.Lambert-St Louis
2 Dec
STL7:33 a.m.Lambert-St Louis
5h 36m
1 stop
YOW2:09 p.m.Ottawa
C$ 744

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 7 August 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 Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Fri 23/10

7:00 a.m.-7:39 p.m.

1 stop13h 39m

Lambert-St Louis

Mon 26/10

10:35 a.m.-4:44 p.m.

2 stops29h 09m

C$ 605

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Mon 31/8

2:35 p.m.-6:42 p.m.

1 stop5h 07m

Lambert-St Louis

Wed 9/9

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

1 stop6h 35m

C$ 632
Quickest round-trip

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Sat 24/10

10:00 a.m.-2:00 p.m.

1 stop5h 00m

Lambert-St Louis

Mon 26/10

4:05 p.m.-9:50 p.m.

1 stop4h 45m

C$ 640

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Tue 1/12

6:15 a.m.-9:13 p.m.

1 stop15h 58m

Lambert-St Louis

Wed 2/12

6:30 a.m.-1:26 p.m.

1 stop5h 56m

C$ 660

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Tue 1/12

6:15 a.m.-9:13 p.m.

1 stop15h 58m

Lambert-St Louis

Wed 2/12

6:30 a.m.-1:26 p.m.

1 stop5h 56m

C$ 661

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Fri 23/10

7:00 a.m.-7:39 p.m.

1 stop13h 39m

Lambert-St Louis

Mon 26/10

8:34 p.m.-4:44 p.m.

1 stop19h 10m

C$ 668

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Tue 1/12

4:36 p.m.-11:09 p.m.

1 stop7h 33m

Lambert-St Louis

Wed 2/12

7:33 a.m.-9:56 p.m.

2 stops13h 23m

C$ 688

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Tue 1/12

9:55 a.m.-3:41 p.m.

2 stops6h 46m

Lambert-St Louis

Wed 2/12

7:33 a.m.-2:09 p.m.

1 stop5h 36m

C$ 744

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Mon 31/8

6:00 a.m.-3:38 p.m.

3 stops10h 38m

Lambert-St Louis

Wed 9/9

10:53 a.m.-7:52 p.m.

2 stops7h 59m

C$ 827

OttawaSt. Louis

YOW Ottawa - STL Lambert-St Louis

YOWSTL

Ottawa

Sat 24/10

7:00 a.m.-9:13 p.m.

3 stops15h 13m

Lambert-St Louis

Mon 26/10

7:29 a.m.-5:58 p.m.

2 stops9h 29m

C$ 1,211

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 16 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 typical price of a round-trip flight between Ottawa and St. Louis?

Prices are currently low for flights on this route.

Typical prices usually range from C$ 660 to C$ 1,302.
The lowest price recently found on this route was C$ 605.

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$ 403Free CancellationRating
7.4
10,081 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 412Free CancellationRating
7.1
11,436 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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