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Cheap flights from Ottawa to St. Louis from C$ 252

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 6/5. 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.
Air Canada Logo
7:00 a.m. - 12:06 p.m.
YOW
-
STL
6h 06m
1 stop
Air Canada Logo
1:05 p.m. - 8:51 p.m.
STL
-
YOW
6h 46m
1 stop
C$ 410Air Canada
Tue, 5 May - Wed, 6 May
United Airlines Logo
6:25 a.m. - 3:46 p.m.
YOW
-
STL
10h 21m
1 stop
United Airlines Logo
6:00 a.m. - 1:59 p.m.
STL
-
YOW
6h 59m
1 stop
C$ 417United Airlines
Mon, 25 May - Fri, 29 May
Air Canada Logo
7:00 a.m. - 12:06 p.m.
YOW
-
STL
6h 06m
1 stop
Air Canada Logo
7:05 a.m. - 1:05 p.m.
STL
-
YOW
5h 00m
1 stop
C$ 418Air Canada
Fri, 5 Jun - Sun, 7 Jun
United Airlines Logo
5:25 p.m. - 9:13 p.m.
YOW
-
STL
4h 48m
1 stop
United Airlines Logo
6:30 a.m. - 9:35 p.m.
STL
-
YOW
14h 05m
1 stop
C$ 423United Airlines
Tue, 5 May - Wed, 6 May
United Airlines Logo
6:25 a.m. - 9:13 p.m.
YOW
-
STL
15h 48m
1 stop
United Airlines Logo
7:45 a.m. - 9:35 p.m.
STL
-
YOW
12h 50m
1 stop
C$ 424United Airlines
Tue, 5 May - Wed, 6 May
Air Canada Logo
9:15 a.m. - 3:25 p.m.
YOW
-
STL
7h 10m
1 stop
Air Canada Logo
7:05 a.m. - 1:05 p.m.
STL
-
YOW
5h 00m
1 stop
C$ 438Air Canada
Wed, 15 Apr - Wed, 20 May
United Airlines Logo
6:05 a.m. - 3:46 p.m.
YOW
-
STL
10h 41m
2 stops
United Airlines Logo
6:00 a.m. - 2:17 p.m.
STL
-
YOW
7h 17m
2 stops
C$ 497United Airlines
Tue, 26 May - Thu, 28 May
United Airlines Logo
2:00 p.m. - 9:13 p.m.
YOW
-
STL
8h 13m
2 stops
United Airlines Logo
6:30 a.m. - 5:07 p.m.
STL
-
YOW
9h 37m
1 stop
C$ 508United Airlines
Tue, 5 May - Wed, 6 May
United Airlines Logo
2:00 p.m. - 9:13 p.m.
YOW
-
STL
8h 13m
2 stops
United Airlines Logo
7:45 a.m. - 5:07 p.m.
STL
-
YOW
8h 22m
1 stop
C$ 509United Airlines
Tue, 5 May - Wed, 6 May
United Airlines Logo
6:00 a.m. - 12:22 p.m.
YOW
-
STL
7h 22m
2 stops
United Airlines Logo
7:05 a.m. - 1:05 p.m.
STL
-
YOW
5h 00m
1 stop
C$ 519United Airlines
Wed, 15 Apr - Wed, 20 May

Air Canada flights from Ottawa to St. Louis

Our best Air Canada deals on Ottawa to St. Louis flight tickets
Air Canada
5 May
YOW7:00 a.m.Ottawa
6h 06m
1 stop
STL12:06 p.m.Lambert-St Louis
6 May
STL1:05 p.m.Lambert-St Louis
6h 46m
1 stop
YOW8:51 p.m.Ottawa
C$ 410
Air Canada
5 Jun
YOW7:00 a.m.Ottawa
6h 06m
1 stop
STL12:06 p.m.Lambert-St Louis
7 Jun
STL7:05 a.m.Lambert-St Louis
5h 00m
1 stop
YOW1:05 p.m.Ottawa
C$ 418
Air Canada
15 Apr
YOW9:15 a.m.Ottawa
7h 10m
1 stop
STL3:25 p.m.Lambert-St Louis
20 May
STL7:05 a.m.Lambert-St Louis
5h 00m
1 stop
YOW1:05 p.m.Ottawa
C$ 438

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
25 May
YOW6:25 a.m.Ottawa
10h 21m
1 stop
STL3:46 p.m.Lambert-St Louis
29 May
STL6:00 a.m.Lambert-St Louis
6h 59m
1 stop
YOW1:59 p.m.Ottawa
C$ 417
United Airlines
5 May
YOW5:25 p.m.Ottawa
4h 48m
1 stop
STL9:13 p.m.Lambert-St Louis
6 May
STL6:30 a.m.Lambert-St Louis
14h 05m
1 stop
YOW9:35 p.m.Ottawa
C$ 423
United Airlines
5 May
YOW6:25 a.m.Ottawa
15h 48m
1 stop
STL9:13 p.m.Lambert-St Louis
6 May
STL7:45 a.m.Lambert-St Louis
12h 50m
1 stop
YOW9:35 p.m.Ottawa
C$ 424

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 23 March 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 5/5

7:00 a.m.-12:06 p.m.

1 stop6h 06m

Lambert-St Louis

Wed 6/5

1:05 p.m.-8:51 p.m.

1 stop6h 46m

C$ 410

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 25/5

6:25 a.m.-3:46 p.m.

1 stop10h 21m

Lambert-St Louis

Fri 29/5

6:00 a.m.-1:59 p.m.

1 stop6h 59m

C$ 417
Quickest round-trip

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 5/6

7:00 a.m.-12:06 p.m.

1 stop6h 06m

Lambert-St Louis

Sun 7/6

7:05 a.m.-1:05 p.m.

1 stop5h 00m

C$ 418

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

5:25 p.m.-9:13 p.m.

1 stop4h 48m

Lambert-St Louis

Wed 6/5

6:30 a.m.-9:35 p.m.

1 stop14h 05m

C$ 423

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

6:25 a.m.-9:13 p.m.

1 stop15h 48m

Lambert-St Louis

Wed 6/5

7:45 a.m.-9:35 p.m.

1 stop12h 50m

C$ 424

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 15/4

9:15 a.m.-3:25 p.m.

1 stop7h 10m

Lambert-St Louis

Wed 20/5

7:05 a.m.-1:05 p.m.

1 stop5h 00m

C$ 438

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 26/5

6:05 a.m.-3:46 p.m.

2 stops10h 41m

Lambert-St Louis

Thu 28/5

6:00 a.m.-2:17 p.m.

2 stops7h 17m

C$ 497

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

2:00 p.m.-9:13 p.m.

2 stops8h 13m

Lambert-St Louis

Wed 6/5

6:30 a.m.-5:07 p.m.

1 stop9h 37m

C$ 508

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

2:00 p.m.-9:13 p.m.

2 stops8h 13m

Lambert-St Louis

Wed 6/5

7:45 a.m.-5:07 p.m.

1 stop8h 22m

C$ 509

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 15/4

6:00 a.m.-12:22 p.m.

2 stops7h 22m

Lambert-St Louis

Wed 20/5

7:05 a.m.-1:05 p.m.

1 stop5h 00m

C$ 519

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 12 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

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

You could potentially save up to 25% 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

6h 57m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 6h 57m
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. 6h 57m 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
Air CanadaPriceFrom C$ 462Free CancellationRating
7.1
10,835 reviews
Search Air Canada flights
United AirlinesPriceFrom C$ 477Free CancellationRating
7.4
9,462 reviews
Search United Airlines 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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