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Cheap flights from Ottawa to St. Louis from C$ 260

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 11/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Ottawa to St. Louis

Cheap round-trip flights

Logo
3:50 p.m. - 10:02 a.m.YOW-STL
19h 12m1 stop
Logo
7:15 p.m. - 4:57 p.m.STL-YOW
20h 42m2 stops
C$ 522
Find Deal
sáb., 11 oct. - sáb., 18 oct.
Logo
3:50 p.m. - 10:02 a.m.YOW-STL
19h 12m1 stop
Logo
4:33 p.m. - 4:57 p.m.STL-YOW
23h 24m1 stop
C$ 534
Find Deal
sáb., 11 oct. - sáb., 18 oct.
United Airlines Logo
11:55 a.m. - 12:44 p.m.YOW-STL
25h 49m2 stops
United Airlines Logo
1:35 p.m. - 10:26 a.m.STL-YOW
19h 51m2 stops
C$ 601United Airlines
Find Deal
vie., 24 oct. - mar., 28 oct.
United Airlines Logo
5:25 p.m. - 6:17 p.m.YOW-STL
25h 52m1 stop
United Airlines Logo
1:35 p.m. - 10:26 a.m.STL-YOW
19h 51m2 stops
C$ 664United Airlines
Find Deal
vie., 24 oct. - mar., 28 oct.
Logo
8:25 a.m. - 10:02 a.m.YOW-STL
26h 37m2 stops
Logo
7:15 p.m. - 4:57 p.m.STL-YOW
20h 42m2 stops
C$ 673
Find Deal
sáb., 11 oct. - sáb., 18 oct.
Logo
7:00 a.m. - 10:02 a.m.YOW-STL
28h 02m3 stops
Logo
7:15 p.m. - 4:57 p.m.STL-YOW
20h 42m2 stops
C$ 693
Find Deal
sáb., 11 oct. - sáb., 18 oct.
Logo
7:00 a.m. - 10:02 a.m.YOW-STL
28h 02m3 stops
Logo
7:15 p.m. - 7:34 p.m.STL-YOW
23h 19m3 stops
C$ 741
Find Deal
sáb., 11 oct. - sáb., 18 oct.
United Airlines Logo
3:10 p.m. - 10:56 p.m.YOW-STL
8h 46m2 stops
United Airlines Logo
7:00 a.m. - 1:34 p.m.STL-YOW
5h 34m1 stop
C$ 810United Airlines
Find Deal
mar., 3 mar. - mié., 4 mar.
United Airlines Logo
5:14 p.m. - 10:00 p.m.YOW-STL
5h 46m1 stop
United Airlines Logo
7:00 a.m. - 1:34 p.m.STL-YOW
5h 34m1 stop
C$ 811United Airlines
Find Deal
mar., 3 mar. - mié., 4 mar.
Logo
5:25 p.m. - 3:44 p.m.YOW-STL
23h 19m1 stop
Logo
4:05 p.m. - 11:08 p.m.STL-YOW
6h 03m1 stop
C$ 817
Find Deal
vie., 24 oct. - mar., 28 oct.

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
24 Oct
YOW11:55 a.m.Ottawa
25h 49m
2 stops
STL12:44 p.m.Lambert-St Louis
28 Oct
STL1:35 p.m.Lambert-St Louis
19h 51m
2 stops
YOW10:26 a.m.Ottawa
C$ 601
Find similar
United Airlines
24 Oct
YOW5:25 p.m.Ottawa
25h 52m
1 stop
STL6:17 p.m.Lambert-St Louis
28 Oct
STL1:35 p.m.Lambert-St Louis
19h 51m
2 stops
YOW10:26 a.m.Ottawa
C$ 664
Find similar
United Airlines
3 Mar
YOW3:10 p.m.Ottawa
8h 46m
2 stops
STL10:56 p.m.Lambert-St Louis
4 Mar
STL7:00 a.m.Lambert-St Louis
5h 34m
1 stop
YOW1:34 p.m.Ottawa
C$ 810
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 15 septiembre 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

sáb. 11/10

3:50 p.m.-10:02 a.m.

1 stop19h 12m

Lambert-St Louis

sáb. 18/10

7:15 p.m.-4:57 p.m.

2 stops20h 42m

C$ 522

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 11/10

3:50 p.m.-10:02 a.m.

1 stop19h 12m

Lambert-St Louis

sáb. 18/10

4:33 p.m.-4:57 p.m.

1 stop23h 24m

C$ 534

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

vie. 24/10

11:55 a.m.-12:44 p.m.

2 stops25h 49m

Lambert-St Louis

mar. 28/10

1:35 p.m.-10:26 a.m.

2 stops19h 51m

C$ 601

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

vie. 24/10

5:25 p.m.-6:17 p.m.

1 stop25h 52m

Lambert-St Louis

mar. 28/10

1:35 p.m.-10:26 a.m.

2 stops19h 51m

C$ 664

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 11/10

8:25 a.m.-10:02 a.m.

2 stops26h 37m

Lambert-St Louis

sáb. 18/10

7:15 p.m.-4:57 p.m.

2 stops20h 42m

C$ 673

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 11/10

7:00 a.m.-10:02 a.m.

3 stops28h 02m

Lambert-St Louis

sáb. 18/10

7:15 p.m.-4:57 p.m.

2 stops20h 42m

C$ 693

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 11/10

7:00 a.m.-10:02 a.m.

3 stops28h 02m

Lambert-St Louis

sáb. 18/10

7:15 p.m.-7:34 p.m.

3 stops23h 19m

C$ 741

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

mar. 3/3

3:10 p.m.-10:56 p.m.

2 stops8h 46m

Lambert-St Louis

mié. 4/3

7:00 a.m.-1:34 p.m.

1 stop5h 34m

C$ 810

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

mar. 3/3

5:14 p.m.-10:00 p.m.

1 stop5h 46m

Lambert-St Louis

mié. 4/3

7:00 a.m.-1:34 p.m.

1 stop5h 34m

C$ 811

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

vie. 24/10

5:25 p.m.-3:44 p.m.

1 stop23h 19m

Lambert-St Louis

mar. 28/10

4:05 p.m.-11:08 p.m.

1 stop6h 03m

C$ 817

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 13 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 September is, on average, the cheapest month to fly to St. Louis from Ottawa, with most prices found around C$ 711. If you don’t want to visit St. Louis in September, then you should wait until April to fly from Ottawa, when ticket prices are also cheap, with an average price of C$ 811.

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$ 789. The most expensive day to fly to St. Louis is Thursday, with ticket prices averaging around C$ 1,024.

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

Direct flights

None
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 23m 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$ 322Free CancellationRating
7.4
8,929 reviews
Search United Airlines flights
Air CanadaPriceFrom C$ 761Free CancellationRating
7.1
10,000 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
Collinsville
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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