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Cheap flights from Ottawa to St. Louis from C$ 389

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Ottawa to St. Louis departing on 2/2. 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.
Multiple Airlines Logo
4:15 p.m. - 6:51 a.m.
YOW
-
STL
39h 36m2 stops
Multiple Airlines Logo
5:42 p.m. - 5:13 p.m.
STL
-
YOW
22h 31m1 stop
C$ 389Multiple Airlines
Mon, 2 Feb - Mon, 9 Feb
United Airlines Logo
5:55 p.m. - 11:59 p.m.
YOW
-
STL
7h 04m1 stop
United Airlines Logo
3:11 p.m. - 9:18 p.m.
STL
-
YOW
5h 07m1 stop
C$ 426United Airlines
Mon, 2 Feb - Mon, 9 Feb
United Airlines Logo
5:55 p.m. - 11:59 p.m.
YOW
-
STL
7h 04m1 stop
United Airlines Logo
6:30 a.m. - 2:27 p.m.
STL
-
YOW
6h 57m2 stops
C$ 431United Airlines
Mon, 19 Jan - Sat, 24 Jan
Multiple Airlines Logo
7:00 a.m. - 6:51 a.m.
YOW
-
STL
24h 51m2 stops
Multiple Airlines Logo
5:42 p.m. - 11:58 p.m.
STL
-
YOW
29h 16m1 stop
C$ 459Multiple Airlines
Sun, 1 Feb - Sun, 8 Feb
Multiple Airlines Logo
4:20 p.m. - 9:21 a.m.
YOW
-
STL
18h 01m1 stop
Multiple Airlines Logo
5:42 p.m. - 11:58 p.m.
STL
-
YOW
29h 16m1 stop
C$ 491Multiple Airlines
Sun, 1 Feb - Sun, 8 Feb
United Airlines Logo
6:00 a.m. - 2:30 p.m.
YOW
-
STL
9h 30m2 stops
United Airlines Logo
6:40 p.m. - 2:30 p.m.
STL
-
YOW
18h 50m2 stops
C$ 504United Airlines
Thu, 8 Jan - Mon, 12 Jan
United Airlines Logo
6:00 a.m. - 2:30 p.m.
YOW
-
STL
9h 30m2 stops
United Airlines Logo
8:05 a.m. - 11:54 p.m.
STL
-
YOW
14h 49m2 stops
C$ 513United Airlines
Sun, 1 Feb - Sun, 8 Feb
Delta Logo
5:40 a.m. - 4:42 p.m.
YOW
-
STL
12h 02m2 stops
Delta Logo
3:58 p.m. - 12:39 a.m.
STL
-
YOW
7h 41m2 stops
C$ 522Delta
Thu, 26 Mar - Mon, 30 Mar
Delta Logo
5:40 a.m. - 4:37 p.m.
YOW
-
STL
11h 57m2 stops
Delta Logo
10:19 a.m. - 12:42 a.m.
STL
-
YOW
13h 23m2 stops
C$ 766Delta
Mon, 19 Jan - Sat, 24 Jan
United Airlines Logo
12:00 p.m. - 10:58 p.m.
YOW
-
STL
11h 58m2 stops
United Airlines Logo
9:57 a.m. - 9:18 p.m.
STL
-
YOW
10h 21m2 stops
C$ 795United Airlines
Mon, 19 Jan - Sat, 24 Jan

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
2 Feb
YOW5:55 p.m.Ottawa
7h 04m
1 stop
STL11:59 p.m.Lambert-St Louis
9 Feb
STL3:11 p.m.Lambert-St Louis
5h 07m
1 stop
YOW9:18 p.m.Ottawa
C$ 426
Find similar
United Airlines
19 Jan
YOW5:55 p.m.Ottawa
7h 04m
1 stop
STL11:59 p.m.Lambert-St Louis
24 Jan
STL6:30 a.m.Lambert-St Louis
6h 57m
2 stops
YOW2:27 p.m.Ottawa
C$ 430
Find similar
United Airlines
8 Jan
YOW6:00 a.m.Ottawa
9h 30m
2 stops
STL2:30 p.m.Lambert-St Louis
12 Jan
STL6:40 p.m.Lambert-St Louis
18h 50m
2 stops
YOW2:30 p.m.Ottawa
C$ 504
Find similar

Delta flights from Ottawa to St. Louis

Our best Delta deals on Ottawa to St. Louis flight tickets
Delta
26 Mar
YOW5:40 a.m.Ottawa
12h 02m
2 stops
STL4:42 p.m.Lambert-St Louis
30 Mar
STL3:58 p.m.Lambert-St Louis
7h 41m
2 stops
YOW12:39 a.m.Ottawa
C$ 522
Find similar
Delta
19 Jan
YOW5:40 a.m.Ottawa
11h 57m
2 stops
STL4:37 p.m.Lambert-St Louis
24 Jan
STL10:19 a.m.Lambert-St Louis
13h 23m
2 stops
YOW12:42 a.m.Ottawa
C$ 766
Find similar
Delta
19 Jan
YOW5:40 a.m.Ottawa
11h 57m
2 stops
STL4:37 p.m.Lambert-St Louis
24 Jan
STL10:19 a.m.Lambert-St Louis
13h 23m
2 stops
YOW12:42 a.m.Ottawa
C$ 807
Find similar

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 21 December 2025.
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

Mon 2/2

4:15 p.m.-6:51 a.m.

2 stops39h 36m

Lambert-St Louis

Mon 9/2

5:42 p.m.-5:13 p.m.

1 stop22h 31m

C$ 389

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 2/2

5:55 p.m.-11:59 p.m.

1 stop7h 04m

Lambert-St Louis

Mon 9/2

3:11 p.m.-9:18 p.m.

1 stop5h 07m

C$ 426

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 19/1

5:55 p.m.-11:59 p.m.

1 stop7h 04m

Lambert-St Louis

Sat 24/1

6:30 a.m.-2:27 p.m.

2 stops6h 57m

C$ 430

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/2

7:00 a.m.-6:51 a.m.

2 stops24h 51m

Lambert-St Louis

Sun 8/2

5:42 p.m.-11:58 p.m.

1 stop29h 16m

C$ 459

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/2

4:20 p.m.-9:21 a.m.

1 stop18h 01m

Lambert-St Louis

Sun 8/2

5:42 p.m.-11:58 p.m.

1 stop29h 16m

C$ 491

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 8/1

6:00 a.m.-2:30 p.m.

2 stops9h 30m

Lambert-St Louis

Mon 12/1

6:40 p.m.-2:30 p.m.

2 stops18h 50m

C$ 504

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 1/2

6:00 a.m.-2:30 p.m.

2 stops9h 30m

Lambert-St Louis

Sun 8/2

8:05 a.m.-11:54 p.m.

2 stops14h 49m

C$ 513

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 26/3

5:40 a.m.-4:42 p.m.

2 stops12h 02m

Lambert-St Louis

Mon 30/3

3:58 p.m.-12:39 a.m.

2 stops7h 41m

C$ 522

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 19/1

5:40 a.m.-4:37 p.m.

2 stops11h 57m

Lambert-St Louis

Sat 24/1

10:19 a.m.-12:42 a.m.

2 stops13h 23m

C$ 766

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 19/1

12:00 p.m.-10:58 p.m.

2 stops11h 58m

Lambert-St Louis

Sat 24/1

9:57 a.m.-9:18 p.m.

2 stops10h 21m

C$ 795

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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 November is, on average, the cheapest month to fly to St. Louis from Ottawa, with most prices found around C$ 684. If you don’t want to visit St. Louis in November, then you should wait until September to fly from Ottawa, when ticket prices are also cheap, with an average price of C$ 709.

What is the cheapest day to depart on your flight to St. Louis?

Our data shows that Monday is the least expensive day to fly to St. Louis. Tickets to fly out on this day can be as low as C$ 787. The most expensive day to fly to St. Louis is Thursday, with ticket prices averaging around C$ 1,021.

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

7h 04m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 7h 04m
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. 7h 04m 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$ 479Free CancellationRating
7.4
9,099 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 489Free CancellationRating
7.1
10,549 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
Litchfield

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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