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Cheap flights from St. Louis to Ottawa from $254

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 1/4. 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
5:11 pm - 5:13 pmSTL-YOW
23h 02m1 stop
Multiple Airlines Logo
9:30 am - 10:34 pmYOW-STL
14h 04m1 stop
$327Multiple Airlines
Find Deal
Tue, Jan 6 - Tue, Jan 13
Air Canada Logo
4:05 pm - 1:38 amSTL-YOW
8h 33m1 stop
Air Canada Logo
10:20 am - 3:29 pmYOW-STL
6h 09m1 stop
$329Air Canada
Find Deal
Mon, Jan 5 - Tue, Jan 13
Multiple Airlines Logo
5:11 pm - 5:13 pmSTL-YOW
23h 02m1 stop
Multiple Airlines Logo
7:00 am - 6:51 amYOW-STL
24h 51m2 stops
$348Multiple Airlines
Find Deal
Tue, Jan 6 - Tue, Jan 13
Air Canada Logo
6:35 pm - 1:32 pmSTL-YOW
17h 57m2 stops
Air Canada Logo
10:20 am - 3:29 pmYOW-STL
6h 09m1 stop
$360Air Canada
Find Deal
Mon, Jan 5 - Tue, Jan 13
United Airlines Logo
3:11 pm - 9:18 pmSTL-YOW
5h 07m1 stop
United Airlines Logo
6:20 am - 2:30 pmYOW-STL
9h 10m1 stop
$362United Airlines
Find Deal
Wed, Jan 7 - Wed, Jan 14
Air Canada Logo
4:05 pm - 11:08 pmSTL-YOW
6h 03m1 stop
Air Canada Logo
9:15 am - 3:29 pmYOW-STL
7h 14m1 stop
$367Air Canada
Find Deal
Wed, Dec 24 - Wed, Dec 31
United Airlines Logo
11:20 am - 11:54 pmSTL-YOW
11h 34m2 stops
United Airlines Logo
5:55 pm - 11:59 pmYOW-STL
7h 04m1 stop
$372United Airlines
Find Deal
Wed, Jan 7 - Wed, Jan 14
United Airlines Logo
9:57 am - 9:56 pmSTL-YOW
10h 59m2 stops
United Airlines Logo
3:10 pm - 10:58 pmYOW-STL
8h 48m2 stops
$377United Airlines
Find Deal
Tue, Jan 6 - Tue, Jan 13
Air Canada Logo
6:35 pm - 1:32 pmSTL-YOW
17h 57m2 stops
Air Canada Logo
12:00 pm - 10:58 pmYOW-STL
11h 58m2 stops
$421Air Canada
Find Deal
Mon, Jan 5 - Tue, Jan 13
Air Canada Logo
6:30 am - 4:23 pmSTL-YOW
8h 53m2 stops
Air Canada Logo
2:15 pm - 10:58 pmYOW-STL
9h 43m2 stops
$452Air Canada
Find Deal
Thu, Jan 22 - Mon, Jan 26

Air Canada flights from St. Louis to Ottawa

Our best Air Canada deals on St. Louis to Ottawa flight tickets
Air Canada
Jan 5
STL4:05 pmLambert-St Louis
8h 33m
1 stop
YOW1:38 amOttawa
Jan 13
YOW10:20 amOttawa
6h 09m
1 stop
STL3:29 pmLambert-St Louis
$329
Find similar
Air Canada
Jan 5
STL6:35 pmLambert-St Louis
17h 57m
2 stops
YOW1:32 pmOttawa
Jan 13
YOW10:20 amOttawa
6h 09m
1 stop
STL3:29 pmLambert-St Louis
$360
Find similar
Air Canada
Dec 24
STL4:05 pmLambert-St Louis
6h 03m
1 stop
YOW11:08 pmOttawa
Dec 31
YOW9:15 amOttawa
7h 14m
1 stop
STL3:29 pmLambert-St Louis
$367
Find similar

American Airlines flights from St. Louis to Ottawa

Our best American Airlines deals on St. Louis to Ottawa flight tickets
American Airlines
Dec 24
STL6:00 amLambert-St Louis
9h 51m
2 stops
YOW4:51 pmOttawa
Dec 31
YOW6:45 amOttawa
10h 38m
2 stops
STL4:23 pmLambert-St Louis
$674
Find similar
American Airlines
Jan 6
STL3:30 pmLambert-St Louis
24h 23m
2 stops
YOW4:53 pmOttawa
Jan 13
YOW6:45 amOttawa
16h 06m
3 stops
STL9:51 pmLambert-St Louis
$722
Find similar
American Airlines
Jan 22
STL6:00 amLambert-St Louis
17h 43m
3 stops
YOW12:43 amOttawa
Jan 26
YOW6:45 amOttawa
15h 30m
2 stops
STL9:15 pmLambert-St Louis
$825
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 November 25, 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

Tue 1/6

5:11 pm-5:13 pm

1 stop23h 02m

Ottawa

Tue 1/13

9:30 am-10:34 pm

1 stop14h 04m

$327

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 1/5

4:05 pm-1:38 am

1 stop8h 33m

Ottawa

Tue 1/13

10:20 am-3:29 pm

1 stop6h 09m

$329

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 1/6

5:11 pm-5:13 pm

1 stop23h 02m

Ottawa

Tue 1/13

7:00 am-6:51 am

2 stops24h 51m

$348

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 1/5

6:35 pm-1:32 pm

2 stops17h 57m

Ottawa

Tue 1/13

10:20 am-3:29 pm

1 stop6h 09m

$360

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 1/7

3:11 pm-9:18 pm

1 stop5h 07m

Ottawa

Wed 1/14

6:20 am-2:30 pm

1 stop9h 10m

$362

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 12/24

4:05 pm-11:08 pm

1 stop6h 03m

Ottawa

Wed 12/31

9:15 am-3:29 pm

1 stop7h 14m

$367

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Wed 1/7

11:20 am-11:54 pm

2 stops11h 34m

Ottawa

Wed 1/14

5:55 pm-11:59 pm

1 stop7h 04m

$372

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Tue 1/6

9:57 am-9:56 pm

2 stops10h 59m

Ottawa

Tue 1/13

3:10 pm-10:58 pm

2 stops8h 48m

$377

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Mon 1/5

6:35 pm-1:32 pm

2 stops17h 57m

Ottawa

Tue 1/13

12:00 pm-10:58 pm

2 stops11h 58m

$421

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 1/22

6:30 am-4:23 pm

2 stops8h 53m

Ottawa

Mon 1/26

2:15 pm-10:58 pm

2 stops9h 43m

$452

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 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

4h 57m

Direct flights

None
The fastest flight from St. Louis to Ottawa takes 4h 57m
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
10,476 reviews
Search Air Canada flights
United AirlinesPriceFrom $362Free CancellationRating
7.4
9,046 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
Calabogie
Brockville
Petawawa
Pembroke
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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