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Cheap flights from St. Louis to Ottawa from $141

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Ottawa departing on 5/14. 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 St. Louis to Ottawa

Cheap round-trip flights

Enter your travel dates to find the best prices.
Air Canada Logo
1:05 pm - 8:46 pm
STL
-
YOW
6h 41m
1 stop
Air Canada Logo
2:00 pm - 8:09 pm
YOW
-
STL
7h 09m
1 stop
$290Air Canada
Wed, May 13 - Wed, May 20
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
Air Canada Logo
7:00 am - 12:06 pm
YOW
-
STL
6h 06m
1 stop
$293Air Canada
Sat, May 16 - Sat, May 23
Air Canada Logo
1:05 pm - 8:46 pm
STL
-
YOW
6h 41m
1 stop
Air Canada Logo
3:00 pm - 8:25 pm
YOW
-
STL
6h 25m
1 stop
$334Air Canada
Wed, May 13 - Sun, May 17
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
Air Canada Logo
3:00 pm - 8:25 pm
YOW
-
STL
6h 25m
1 stop
$338Air Canada
Tue, May 12 - Mon, May 18
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
Air Canada Logo
2:35 pm - 8:25 pm
YOW
-
STL
6h 50m
1 stop
$339Air Canada
Tue, May 12 - Sat, May 16
United Airlines Logo
6:00 am - 9:35 pm
STL
-
YOW
14h 35m
1 stop
United Airlines Logo
6:25 am - 3:46 pm
YOW
-
STL
10h 21m
1 stop
$342United Airlines
Mon, Jun 8 - Wed, Jun 10
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
Air Canada Logo
7:00 am - 12:06 pm
YOW
-
STL
6h 06m
1 stop
$343Air Canada
Fri, May 15 - Fri, May 22
Air Canada Logo
7:45 am - 10:05 pm
STL
-
YOW
13h 20m
2 stops
Air Canada Logo
2:35 pm - 8:25 pm
YOW
-
STL
6h 50m
1 stop
$346Air Canada
Mon, Apr 27 - Mon, May 4
United Airlines Logo
6:00 am - 5:07 pm
STL
-
YOW
10h 07m
1 stop
United Airlines Logo
6:00 am - 3:46 pm
YOW
-
STL
10h 46m
2 stops
$352United Airlines
Mon, Jun 8 - Wed, Jun 10
Air Canada Logo
1:05 pm - 8:46 pm
STL
-
YOW
6h 41m
1 stop
Air Canada Logo
3:00 pm - 8:25 pm
YOW
-
STL
6h 25m
1 stop
$358Air Canada
Mon, May 11 - Mon, May 18

Air Canada flights from St. Louis to Ottawa

Our best Air Canada deals on St. Louis to Ottawa flight tickets
Air Canada
May 13
STL1:05 pmLambert-St Louis
6h 41m
1 stop
YOW8:46 pmOttawa
May 20
YOW2:00 pmOttawa
7h 09m
1 stop
STL8:09 pmLambert-St Louis
$290
Air Canada
May 16
STL7:05 amLambert-St Louis
5h 00m
1 stop
YOW1:05 pmOttawa
May 23
YOW7:00 amOttawa
6h 06m
1 stop
STL12:06 pmLambert-St Louis
$293
Air Canada
May 13
STL1:05 pmLambert-St Louis
6h 41m
1 stop
YOW8:46 pmOttawa
May 17
YOW3:00 pmOttawa
6h 25m
1 stop
STL8:25 pmLambert-St Louis
$334

United Airlines flights from St. Louis to Ottawa

Our best United Airlines deals on St. Louis to Ottawa flight tickets
United Airlines
Jun 8
STL6:00 amLambert-St Louis
14h 35m
1 stop
YOW9:35 pmOttawa
Jun 10
YOW6:25 amOttawa
10h 21m
1 stop
STL3:46 pmLambert-St Louis
$342
United Airlines
Jun 8
STL6:00 amLambert-St Louis
10h 07m
1 stop
YOW5:07 pmOttawa
Jun 10
YOW6:00 amOttawa
10h 46m
2 stops
STL3:46 pmLambert-St Louis
$352
United Airlines
May 12
STL7:45 amLambert-St Louis
8h 22m
1 stop
YOW5:07 pmOttawa
May 16
YOW4:00 pmOttawa
8h 19m
2 stops
STL11:19 pmLambert-St Louis
$430

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Ottawa 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 April 1, 2026.
Use the filters below to find and compare flights from St. Louis to Ottawa that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 5/13

1:05 pm-8:46 pm

1 stop6h 41m

Ottawa

Wed 5/20

2:00 pm-8:09 pm

1 stop7h 09m

$290
Quickest round-trip

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sat 5/16

7:05 am-1:05 pm

1 stop5h 00m

Ottawa

Sat 5/23

7:00 am-12:06 pm

1 stop6h 06m

$293

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 5/13

1:05 pm-8:46 pm

1 stop6h 41m

Ottawa

Sun 5/17

3:00 pm-8:25 pm

1 stop6h 25m

$334

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 5/12

7:05 am-1:05 pm

1 stop5h 00m

Ottawa

Mon 5/18

3:00 pm-8:25 pm

1 stop6h 25m

$338

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 5/12

7:05 am-1:05 pm

1 stop5h 00m

Ottawa

Sat 5/16

2:35 pm-8:25 pm

1 stop6h 50m

$339

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 6/8

6:00 am-9:35 pm

1 stop14h 35m

Ottawa

Wed 6/10

6:25 am-3:46 pm

1 stop10h 21m

$342

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Fri 5/15

7:05 am-1:05 pm

1 stop5h 00m

Ottawa

Fri 5/22

7:00 am-12:06 pm

1 stop6h 06m

$343

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 4/27

7:45 am-10:05 pm

2 stops13h 20m

Ottawa

Mon 5/4

2:35 pm-8:25 pm

1 stop6h 50m

$346

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 6/8

6:00 am-5:07 pm

1 stop10h 07m

Ottawa

Wed 6/10

6:00 am-3:46 pm

2 stops10h 46m

$352

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 5/11

1:05 pm-8:46 pm

1 stop6h 41m

Ottawa

Mon 5/18

3:00 pm-8:25 pm

1 stop6h 25m

$358

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 Ottawa from

How to get the cheapest flight ticket from St. Louis to Ottawa

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 St. Louis and Ottawa?

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

You could potentially save up to 8% on your flight if you consider stops on a St. Louis to Ottawa flight.

When to book flights from St. Louis to Ottawa

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Ottawa according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Ottawa (STL to YOW) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Ottawa

Fastest flight time

9h 37m

Direct flights

None
The fastest flight from St. Louis to Ottawa takes 9h 37m
There are no direct flights from St. Louis to Ottawa. There are no popular flight routes from St. Louis to Ottawa.
Search flight deals

  • How far is Lambert-St Louis to Ottawa by plane?

    There are 877.2 mi between Lambert-St Louis and Ottawa. By plane, this route typically takes 9h 37m.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Ottawa Airport?

    Prices for flights from Lambert-St Louis Airport to Ottawa Airport are updated daily.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Ottawa Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Ottawa Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Ottawa Airport.

  • What documentation or ID do you need to fly to Ottawa Airport?

    The required travel and health documents for your Ottawa Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ottawa Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular airline from St. Louis to Ottawa?

Best airlines flying from St. Louis to Ottawa

Compare and see reviews for airlines that fly from St. Louis to Ottawa with momondo
Airline
Rating
Free Cancellation
Price
Air CanadaPriceFrom $139Free CancellationRating
7.1
10,873 reviews
Search Air Canada flights
United AirlinesPriceFrom $359Free CancellationRating
7.4
9,529 reviews
Search United Airlines flights

Traveling to a place near Ottawa?

Book flights to Ottawa if you plan to visit one of these locations
Gatineau
Pembroke
Calabogie
Petawawa
Smiths Falls
Brockville
Perth
Prescott
Winchester
Wakefield

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from St. Louis to Ottawa. Millions of users trust and use momondo every year so you are in good hands.

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

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

How can momondo help me find flights from St. Louis to Ottawa?

momondo provides multiple filters to help you find the best flight to Ottawa from St. Louis. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from St. Louis to Ottawa right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to Ottawa from St. Louis. 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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