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Cheap flights from Ottawa to St. Louis from $246

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 2/10. 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
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.
United Airlines Logo
5:20 pm - 9:08 pm
YOW
-
STL
4h 48m
1 stop
United Airlines Logo
7:45 am - 1:59 pm
STL
-
YOW
5h 14m
1 stop
$318United Airlines
Thu, Apr 9 - Sat, Apr 11
United Airlines Logo
6:00 am - 9:08 pm
YOW
-
STL
16h 08m
3 stops
United Airlines Logo
7:45 am - 1:59 pm
STL
-
YOW
5h 14m
1 stop
$328United Airlines
Thu, Apr 9 - Sat, Apr 11
Air Canada Logo
7:15 am - 3:29 pm
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
4:05 pm - 11:18 pm
STL
-
YOW
6h 13m
1 stop
$367Air Canada
Sun, Mar 1 - Wed, Mar 4
Air Canada Logo
7:15 am - 3:29 pm
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
4:05 pm - 11:18 pm
STL
-
YOW
6h 13m
1 stop
$368Air Canada
Sun, Mar 1 - Wed, Mar 4
Air Canada Logo
9:15 am - 3:24 pm
YOW
-
STL
7h 09m
1 stop
Air Canada Logo
7:45 am - 7:34 pm
STL
-
YOW
10h 49m
2 stops
$387Air Canada
Thu, Apr 9 - Sat, Apr 11
Air Canada Logo
7:15 am - 3:29 pm
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
7:41 am - 5:41 pm
STL
-
YOW
9h 00m
2 stops
$416Air Canada
Sun, Mar 1 - Wed, Mar 4
Air Canada Logo
7:15 am - 3:29 pm
YOW
-
STL
9h 14m
1 stop
Air Canada Logo
7:41 am - 4:23 pm
STL
-
YOW
7h 42m
2 stops
$417Air Canada
Sun, Mar 1 - Wed, Mar 4
United Airlines Logo
5:00 am - 9:05 pm
YOW
-
STL
17h 05m
2 stops
United Airlines Logo
6:25 am - 2:27 pm
STL
-
YOW
7h 02m
2 stops
$418United Airlines
Sun, Mar 1 - Wed, Mar 4
United Airlines Logo
5:00 am - 9:05 pm
YOW
-
STL
17h 05m
2 stops
United Airlines Logo
7:41 am - 5:18 pm
STL
-
YOW
8h 37m
2 stops
$427United Airlines
Sun, Mar 1 - Wed, Mar 4
Delta Logo
5:40 am - 4:42 pm
YOW
-
STL
12h 02m
2 stops
Delta Logo
10:14 am - 12:39 am
STL
-
YOW
13h 25m
2 stops
$439Delta
Sun, Mar 1 - Wed, Mar 4

Air Canada flights from Ottawa to St. Louis

Our best Air Canada deals on Ottawa to St. Louis flight tickets
Air Canada
Mar 1
YOW7:15 amOttawa
9h 14m
1 stop
STL3:29 pmLambert-St Louis
Mar 4
STL4:05 pmLambert-St Louis
6h 13m
1 stop
YOW11:18 pmOttawa
$367
Air Canada
Mar 1
YOW7:15 amOttawa
9h 14m
1 stop
STL3:29 pmLambert-St Louis
Mar 4
STL4:05 pmLambert-St Louis
6h 13m
1 stop
YOW11:18 pmOttawa
$368
Air Canada
Apr 9
YOW9:15 amOttawa
7h 09m
1 stop
STL3:24 pmLambert-St Louis
Apr 11
STL7:45 amLambert-St Louis
10h 49m
2 stops
YOW7:34 pmOttawa
$387

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
Apr 9
YOW5:20 pmOttawa
4h 48m
1 stop
STL9:08 pmLambert-St Louis
Apr 11
STL7:45 amLambert-St Louis
5h 14m
1 stop
YOW1:59 pmOttawa
$318
United Airlines
Apr 9
YOW6:00 amOttawa
16h 08m
3 stops
STL9:08 pmLambert-St Louis
Apr 11
STL7:45 amLambert-St Louis
5h 14m
1 stop
YOW1:59 pmOttawa
$328
United Airlines
Mar 1
YOW5:00 amOttawa
17h 05m
2 stops
STL9:05 pmLambert-St Louis
Mar 4
STL6:25 amLambert-St Louis
7h 02m
2 stops
YOW2:27 pmOttawa
$418

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 832,500 searches. Data last updated February 4, 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

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 4/9

5:20 pm-9:08 pm

1 stop4h 48m

Lambert-St Louis

Sat 4/11

7:45 am-1:59 pm

1 stop5h 14m

$318

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 4/9

6:00 am-9:08 pm

3 stops16h 08m

Lambert-St Louis

Sat 4/11

7:45 am-1:59 pm

1 stop5h 14m

$328

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

7:15 am-3:29 pm

1 stop9h 14m

Lambert-St Louis

Wed 3/4

4:05 pm-11:18 pm

1 stop6h 13m

$367

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

7:15 am-3:29 pm

1 stop9h 14m

Lambert-St Louis

Wed 3/4

4:05 pm-11:18 pm

1 stop6h 13m

$368

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 4/9

9:15 am-3:24 pm

1 stop7h 09m

Lambert-St Louis

Sat 4/11

7:45 am-7:34 pm

2 stops10h 49m

$387

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

7:15 am-3:29 pm

1 stop9h 14m

Lambert-St Louis

Wed 3/4

7:41 am-5:41 pm

2 stops9h 00m

$416

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

7:15 am-3:29 pm

1 stop9h 14m

Lambert-St Louis

Wed 3/4

7:41 am-4:23 pm

2 stops7h 42m

$417

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

5:00 am-9:05 pm

2 stops17h 05m

Lambert-St Louis

Wed 3/4

6:25 am-2:27 pm

2 stops7h 02m

$418

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

5:00 am-9:05 pm

2 stops17h 05m

Lambert-St Louis

Wed 3/4

7:41 am-5:18 pm

2 stops8h 37m

$427

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Sun 3/1

5:40 am-4:42 pm

2 stops12h 02m

Lambert-St Louis

Wed 3/4

10:14 am-12:39 am

2 stops13h 25m

$439

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 14 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?

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

In general, January is the cheapest month to fly from Ottawa to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $406. The month of November is another great option to travel to St. Louis, with average flight prices from Ottawa averaging around $496.

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 48m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 4h 48m
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?

    The straight-line distance from Ottawa to Lambert-St Louis is 877.2 mi. By plane, this route typically takes 4h 48m.

  • 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?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for 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 $350Free CancellationRating
7.1
10,688 reviews
Search Air Canada flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Maryland Heights
Florissant
O'Fallon
Collinsville
St. Peters
Fenton
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Litchfield
Glencoe
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Ottawa to St. Louis?

Finding the right flight to St. Louis from Ottawa is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to St. Louis quick and easy, saving you time and money.

Can I find flights from Ottawa to St. Louis with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to St. Louis from Ottawa with this policy.

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?

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Ottawa and alert you when they change.

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