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Cheap flights from St. Louis to Ottawa from $314

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Ottawa departing on 1/25. 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 St. Louis to Ottawa

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
5:42 pm - 5:13 pm
STL
-
YOW
22h 31m1 stop
Multiple Airlines Logo
7:00 am - 6:51 am
YOW
-
STL
24h 51m2 stops
$314Multiple Airlines
Sun, Jan 25 - Sun, Feb 1
Multiple Airlines Logo
5:42 pm - 5:13 pm
STL
-
YOW
22h 31m1 stop
Multiple Airlines Logo
4:20 pm - 9:21 am
YOW
-
STL
18h 01m1 stop
$325Multiple Airlines
Sun, Jan 25 - Sun, Feb 1
Multiple Airlines Logo
5:11 pm - 11:58 pm
STL
-
YOW
29h 47m1 stop
Multiple Airlines Logo
7:00 am - 6:51 am
YOW
-
STL
24h 51m2 stops
$348Multiple Airlines
Tue, Jan 6 - Tue, Jan 13
United Airlines Logo
8:30 am - 2:27 pm
STL
-
YOW
4h 57m1 stop
United Airlines Logo
5:11 pm - 9:00 pm
YOW
-
STL
4h 49m1 stop
$361United Airlines
Wed, Mar 4 - Wed, Mar 18
Air Canada Logo
4:05 pm - 11:08 pm
STL
-
YOW
6h 03m1 stop
Air Canada Logo
9:15 am - 3:29 pm
YOW
-
STL
7h 14m1 stop
$362Air Canada
Tue, Jan 6 - Tue, Jan 13
United Airlines Logo
8:30 am - 2:27 pm
STL
-
YOW
4h 57m1 stop
United Airlines Logo
6:20 am - 9:00 pm
YOW
-
STL
15h 40m1 stop
$363United Airlines
Wed, Mar 4 - Wed, Mar 18
United Airlines Logo
6:30 am - 2:27 pm
STL
-
YOW
6h 57m2 stops
United Airlines Logo
5:11 pm - 10:58 pm
YOW
-
STL
6h 47m1 stop
$372United Airlines
Sun, Jan 18 - Wed, Jan 21
United Airlines Logo
7:41 am - 5:07 pm
STL
-
YOW
8h 26m1 stop
United Airlines Logo
2:15 pm - 9:00 pm
YOW
-
STL
7h 45m2 stops
$373United Airlines
Wed, Mar 4 - Wed, Mar 18
United Airlines Logo
6:30 am - 4:30 pm
STL
-
YOW
9h 00m2 stops
United Airlines Logo
3:10 pm - 10:58 pm
YOW
-
STL
8h 48m2 stops
$378United Airlines
Sun, Jan 18 - Wed, Jan 21
United Airlines Logo
7:41 am - 9:18 pm
STL
-
YOW
12h 37m2 stops
United Airlines Logo
5:11 pm - 9:00 pm
YOW
-
STL
4h 49m1 stop
$450United Airlines
Thu, Mar 12 - Sun, Mar 22

United Airlines flights from St. Louis to Ottawa

Our best United Airlines deals on St. Louis to Ottawa flight tickets
United Airlines
Mar 4
STL8:30 amLambert-St Louis
4h 57m
1 stop
YOW2:27 pmOttawa
Mar 18
YOW5:11 pmOttawa
4h 49m
1 stop
STL9:00 pmLambert-St Louis
$361
Find similar
United Airlines
Mar 4
STL8:30 amLambert-St Louis
4h 57m
1 stop
YOW2:27 pmOttawa
Mar 18
YOW6:20 amOttawa
15h 40m
1 stop
STL9:00 pmLambert-St Louis
$363
Find similar
United Airlines
Jan 18
STL6:30 amLambert-St Louis
6h 57m
2 stops
YOW2:27 pmOttawa
Jan 21
YOW5:11 pmOttawa
6h 47m
1 stop
STL10:58 pmLambert-St Louis
$372
Find similar

American Airlines flights from St. Louis to Ottawa

Our best American Airlines deals on St. Louis to Ottawa flight tickets
American Airlines
Mar 14
STL6:33 pmLambert-St Louis
21h 18m
2 stops
YOW4:51 pmOttawa
Mar 23
YOW6:45 amOttawa
18h 07m
2 stops
STL11:52 pmLambert-St Louis
$677
Find similar
American Airlines
Jan 6
STL6:00 amLambert-St Louis
17h 43m
2 stops
YOW12:43 amOttawa
Jan 13
YOW6:45 amOttawa
16h 06m
3 stops
STL9:51 pmLambert-St Louis
$723
Find similar
American Airlines
Jan 25
STL6:00 amLambert-St Louis
9h 53m
2 stops
YOW4:53 pmOttawa
Feb 1
YOW6:45 amOttawa
16h 06m
3 stops
STL9:51 pmLambert-St Louis
$750
Find similar

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 December 11, 2025.
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

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sun 1/25

5:42 pm-5:13 pm

1 stop22h 31m

Ottawa

Sun 2/1

7:00 am-6:51 am

2 stops24h 51m

$314

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sun 1/25

5:42 pm-5:13 pm

1 stop22h 31m

Ottawa

Sun 2/1

4:20 pm-9:21 am

1 stop18h 01m

$325

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 1/6

5:11 pm-11:58 pm

1 stop29h 47m

Ottawa

Tue 1/13

7:00 am-6:51 am

2 stops24h 51m

$348

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 3/4

8:30 am-2:27 pm

1 stop4h 57m

Ottawa

Wed 3/18

5:11 pm-9:00 pm

1 stop4h 49m

$361

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 1/6

4:05 pm-11:08 pm

1 stop6h 03m

Ottawa

Tue 1/13

9:15 am-3:29 pm

1 stop7h 14m

$362

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 3/4

8:30 am-2:27 pm

1 stop4h 57m

Ottawa

Wed 3/18

6:20 am-9:00 pm

1 stop15h 40m

$363

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sun 1/18

6:30 am-2:27 pm

2 stops6h 57m

Ottawa

Wed 1/21

5:11 pm-10:58 pm

1 stop6h 47m

$372

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 3/4

7:41 am-5:07 pm

1 stop8h 26m

Ottawa

Wed 3/18

2:15 pm-9:00 pm

2 stops7h 45m

$373

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Sun 1/18

6:30 am-4:30 pm

2 stops9h 00m

Ottawa

Wed 1/21

3:10 pm-10:58 pm

2 stops8h 48m

$378

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 3/12

7:41 am-9:18 pm

2 stops12h 37m

Ottawa

Sun 3/22

5:11 pm-9:00 pm

1 stop4h 49m

$450

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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 cheapest day to depart on your flight to Ottawa?

The cheapest day to depart from St. Louis to Ottawa is on a Saturday. Travelers who choose to depart for Ottawa on a Saturday will often find tickets for as low as $407. Be sure to avoid booking your departure on a Monday as prices are generally higher than usual. According to our data, the average ticket price to Ottawa on Monday is $860.

What is the cheapest time of day to depart on your flight to Ottawa?

In the afternoon is the cheapest time of day to fly from St. Louis to Ottawa when you can find flight prices for as low as $615. Flying to Ottawa in the afternoon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $682 on average. Flights to Ottawa from St. Louis in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

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

You could potentially save up to 18% 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

5h 05m

Direct flights

None
The fastest flight from St. Louis to Ottawa takes 5h 05m
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 5h 05m.

  • 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 $330Free CancellationRating
7.1
10,516 reviews
Search Air Canada flights
United AirlinesPriceFrom $362Free CancellationRating
7.4
9,095 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
Brockville
Calabogie
Petawawa
Smiths Falls
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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