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Cheap flights from St. Louis to Ottawa from $184

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 9/30. 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

Discover deals from 900+ travel sites with momondo.

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
6:39 pm - 2:33 pmSTL  Lambert-St Louis-YOW Ottawa
18h 54m1 stop Orlando
Multiple Airlines Logo
8:15 pm - 1:10 pmYOW  Ottawa-STL Lambert-St Louis
17h 55m2 stops Calgary Atlanta Hartsfield-Jackson
$463Multiple Airlines
Thu, Sep 10 - Thu, Sep 17
Air Canada Logo
12:10 pm - 7:45 pmSTL  Lambert-St Louis-YOW Ottawa
6h 35m1 stop Montreal Pierre Elliott Trudeau Intl
Air Canada Logo
2:45 pm - 6:41 pmYOW  Ottawa-STL Lambert-St Louis
4h 56m1 stop Montreal Pierre Elliott Trudeau Intl
$574Air Canada
Tue, Sep 22 - Fri, Sep 25
Air Canada Logo
8:55 am - 3:10 pmSTL  Lambert-St Louis-YOW Ottawa
5h 15m1 stop Toronto Pearson Intl
Air Canada Logo
2:45 pm - 6:41 pmYOW  Ottawa-STL Lambert-St Louis
4h 56m1 stop Montreal Pierre Elliott Trudeau Intl
$579Air Canada
Tue, Sep 22 - Fri, Sep 25
Air Canada Logo
8:55 am - 3:10 pmSTL  Lambert-St Louis-YOW Ottawa
5h 15m1 stop Toronto Pearson Intl
Air Canada Logo
2:35 pm - 6:41 pmYOW  Ottawa-STL Lambert-St Louis
5h 06m1 stop Montreal Pierre Elliott Trudeau Intl
$579Air Canada
Thu, Oct 1 - Tue, Oct 6
United Airlines Logo
8:00 am - 1:59 pmSTL  Lambert-St Louis-YOW Ottawa
4h 59m1 stop Chicago O'Hare Intl
United Airlines Logo
5:20 pm - 9:21 pmYOW  Ottawa-STL Lambert-St Louis
5h 01m1 stop Chicago O'Hare Intl
$584United Airlines
Thu, Oct 1 - Thu, Oct 1
Multiple Airlines Logo
6:39 pm - 2:33 pmSTL  Lambert-St Louis-YOW Ottawa
18h 54m1 stop Orlando
Multiple Airlines Logo
2:10 pm - 1:10 pmYOW  Ottawa-STL Lambert-St Louis
24h 00m2 stops Newark Atlanta Hartsfield-Jackson
$586Multiple Airlines
Thu, Oct 1 - Tue, Oct 6
Multiple Airlines Logo
12:17 pm - 5:35 amSTL  Lambert-St Louis-YOW Ottawa
16h 18m2 stops Las Vegas Harry Reid Intl Calgary
Multiple Airlines Logo
7:00 am - 4:34 pmYOW  Ottawa-STL Lambert-St Louis
10h 34m1 stop Orlando
$592Multiple Airlines
Tue, Sep 22 - Fri, Sep 25
United Airlines Logo
8:30 am - 6:55 pmSTL  Lambert-St Louis-YOW Ottawa
9h 25m2 stops Chicago O'Hare Intl Washington, D.C. Dulles Intl
United Airlines Logo
5:20 pm - 9:21 pmYOW  Ottawa-STL Lambert-St Louis
5h 01m1 stop Chicago O'Hare Intl
$594United Airlines
Tue, Sep 22 - Fri, Sep 25
Multiple Airlines Logo
5:19 pm - 11:48 pmSTL  Lambert-St Louis-YOW Ottawa
29h 29m1 stop Orlando
Multiple Airlines Logo
8:15 pm - 1:10 pmYOW  Ottawa-STL Lambert-St Louis
17h 55m2 stops Calgary Atlanta Hartsfield-Jackson
$600Multiple Airlines
Sun, Sep 27 - Thu, Oct 1
United Airlines Logo
6:00 am - 2:10 pmSTL  Lambert-St Louis-YOW Ottawa
7h 10m2 stops Chicago O'Hare Intl Washington, D.C. Reagan-National
United Airlines Logo
5:20 pm - 9:21 pmYOW  Ottawa-STL Lambert-St Louis
5h 01m1 stop Chicago O'Hare Intl
$648United Airlines
Thu, Oct 1 - Thu, Oct 1

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WestJet flights from St. Louis to Ottawa

Our best WestJet deals on St. Louis to Ottawa flight tickets
WestJet
Oct 1
STL6:40 amLambert-St Louis
21h 55m
2 stops
YOW5:35 amOttawa
Oct 6
YOW8:15 pmOttawa
13h 54m
2 stops
STL9:09 amLambert-St Louis
$647
WestJet
Sep 27
STL6:40 amLambert-St Louis
21h 55m
2 stops
YOW5:35 amOttawa
Oct 1
YOW12:25 pmOttawa
11h 51m
2 stops
STL11:16 pmLambert-St Louis
$681
WestJet
Sep 25
STL5:59 pmLambert-St Louis
34h 36m
2 stops
YOW5:35 amOttawa
Sep 27
YOW4:15 pmOttawa
32h 01m
2 stops
STL11:16 pmLambert-St Louis
$690

American Airlines flights from St. Louis to Ottawa

Our best American Airlines deals on St. Louis to Ottawa flight tickets
American Airlines
Sep 10
STL6:00 amLambert-St Louis
13h 00m
2 stops
YOW8:00 pmOttawa
Sep 12
YOW7:00 amOttawa
16h 42m
3 stops
STL10:42 pmLambert-St Louis
$832
American Airlines
Sep 10
STL5:00 amLambert-St Louis
14h 00m
3 stops
YOW8:00 pmOttawa
Sep 17
YOW7:00 amOttawa
18h 27m
2 stops
STL12:27 amLambert-St Louis
$837
American Airlines
Oct 1
STL5:00 amLambert-St Louis
14h 00m
3 stops
YOW8:00 pmOttawa
Oct 6
YOW7:00 amOttawa
14h 32m
2 stops
STL8:32 pmLambert-St Louis
$841

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 August 17, 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 Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 9/10

6:39 pm-2:33 pm

1 stop18h 54m

Ottawa

Thu 9/17

8:15 pm-1:10 pm

2 stops17h 55m

$463

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Tue 9/22

12:10 pm-7:45 pm

1 stop6h 35m

Ottawa

Fri 9/25

2:45 pm-6:41 pm

1 stop4h 56m

$574

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Tue 9/22

8:55 am-3:10 pm

1 stop5h 15m

Ottawa

Fri 9/25

2:45 pm-6:41 pm

1 stop4h 56m

$579

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 10/1

8:55 am-3:10 pm

1 stop5h 15m

Ottawa

Tue 10/6

2:35 pm-6:41 pm

1 stop5h 06m

$579
Quickest round-trip

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 10/1

8:00 am-1:59 pm

1 stop4h 59m

Ottawa

Thu 10/1

5:20 pm-9:21 pm

1 stop5h 01m

$584

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 10/1

6:39 pm-2:33 pm

1 stop18h 54m

Ottawa

Tue 10/6

2:10 pm-1:10 pm

2 stops24h 00m

$586

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Tue 9/22

12:17 pm-5:35 am

2 stops16h 18m

Ottawa

Fri 9/25

7:00 am-4:34 pm

1 stop10h 34m

$592

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Tue 9/22

8:30 am-6:55 pm

2 stops9h 25m

Ottawa

Fri 9/25

5:20 pm-9:21 pm

1 stop5h 01m

$594

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Sun 9/27

5:19 pm-11:48 pm

1 stop29h 29m

Ottawa

Thu 10/1

8:15 pm-1:10 pm

2 stops17h 55m

$600

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 10/1

6:00 am-2:10 pm

2 stops7h 10m

Ottawa

Thu 10/1

5:20 pm-9:21 pm

1 stop5h 01m

$648

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 typical price of a round-trip flight between St. Louis and Ottawa?

Prices are currently low for flights on this route.

Typical prices usually range from $472 to $704.
The lowest price recently found on this route was $463.

What is the cheapest month to fly to Ottawa?

In general, October is the cheapest month to fly from St. Louis to Ottawa. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $0. The month of January is another great option to travel to Ottawa, with average flight prices from St. Louis averaging around $0.

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

You could potentially save up to 40% 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 49m

Direct flights

None
The fastest flight from St. Louis to Ottawa takes 5h 49m
There are no direct flights from St. Louis to Ottawa. There are no popular flight routes from St. Louis to Ottawa.
Search flight deals

Frequently asked questions about flying from St. Louis to Ottawa

  • 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 49m.

  • 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
11,485 reviews
Search Air Canada flights
United AirlinesPriceFrom $203Free CancellationRating
7.4
10,106 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
Brockville
Pembroke
Petawawa
Calabogie
Smiths Falls
Perth
Prescott
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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