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Cheap flights from Ottawa to St. Louis 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 Ottawa to St. Louis departing on 5/6. 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 Ottawa to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Air Canada Logo
7:00 am - 12:06 pm
YOW
-
STL
6h 06m
1 stop
Air Canada Logo
1:05 pm - 8:51 pm
STL
-
YOW
6h 46m
1 stop
$299Air Canada
Tue, May 5 - Wed, May 6
United Airlines Logo
6:25 am - 3:46 pm
YOW
-
STL
10h 21m
1 stop
United Airlines Logo
6:00 am - 1:59 pm
STL
-
YOW
6h 59m
1 stop
$304United Airlines
Mon, May 25 - Fri, May 29
Air Canada Logo
7:00 am - 12:06 pm
YOW
-
STL
6h 06m
1 stop
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
$305Air Canada
Fri, Jun 5 - Sun, Jun 7
United Airlines Logo
5:25 pm - 9:13 pm
YOW
-
STL
4h 48m
1 stop
United Airlines Logo
6:30 am - 9:35 pm
STL
-
YOW
14h 05m
1 stop
$308United Airlines
Tue, May 5 - Wed, May 6
United Airlines Logo
6:25 am - 9:13 pm
YOW
-
STL
15h 48m
1 stop
United Airlines Logo
7:45 am - 9:35 pm
STL
-
YOW
12h 50m
1 stop
$309United Airlines
Tue, May 5 - Wed, May 6
Air Canada Logo
9:15 am - 3:25 pm
YOW
-
STL
7h 10m
1 stop
Air Canada Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
$319Air Canada
Wed, Apr 15 - Wed, May 20
United Airlines Logo
6:05 am - 3:46 pm
YOW
-
STL
10h 41m
2 stops
United Airlines Logo
6:00 am - 2:17 pm
STL
-
YOW
7h 17m
2 stops
$362United Airlines
Tue, May 26 - Thu, May 28
United Airlines Logo
2:00 pm - 9:13 pm
YOW
-
STL
8h 13m
2 stops
United Airlines Logo
6:30 am - 5:07 pm
STL
-
YOW
9h 37m
1 stop
$370United Airlines
Tue, May 5 - Wed, May 6
United Airlines Logo
2:00 pm - 9:13 pm
YOW
-
STL
8h 13m
2 stops
United Airlines Logo
7:45 am - 5:07 pm
STL
-
YOW
8h 22m
1 stop
$371United Airlines
Tue, May 5 - Wed, May 6
United Airlines Logo
6:00 am - 12:22 pm
YOW
-
STL
7h 22m
2 stops
United Airlines Logo
7:05 am - 1:05 pm
STL
-
YOW
5h 00m
1 stop
$378United Airlines
Wed, Apr 15 - Wed, May 20

Air Canada flights from Ottawa to St. Louis

Our best Air Canada deals on Ottawa to St. Louis flight tickets
Air Canada
May 5
YOW7:00 amOttawa
6h 06m
1 stop
STL12:06 pmLambert-St Louis
May 6
STL1:05 pmLambert-St Louis
6h 46m
1 stop
YOW8:51 pmOttawa
$299
Air Canada
Jun 5
YOW7:00 amOttawa
6h 06m
1 stop
STL12:06 pmLambert-St Louis
Jun 7
STL7:05 amLambert-St Louis
5h 00m
1 stop
YOW1:05 pmOttawa
$305
Air Canada
Apr 15
YOW9:15 amOttawa
7h 10m
1 stop
STL3:25 pmLambert-St Louis
May 20
STL7:05 amLambert-St Louis
5h 00m
1 stop
YOW1:05 pmOttawa
$319

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
May 25
YOW6:25 amOttawa
10h 21m
1 stop
STL3:46 pmLambert-St Louis
May 29
STL6:00 amLambert-St Louis
6h 59m
1 stop
YOW1:59 pmOttawa
$304
United Airlines
May 5
YOW5:25 pmOttawa
4h 48m
1 stop
STL9:13 pmLambert-St Louis
May 6
STL6:30 amLambert-St Louis
14h 05m
1 stop
YOW9:35 pmOttawa
$308
United Airlines
May 5
YOW5:50 pmOttawa
7h 07m
1 stop
STL11:57 pmLambert-St Louis
May 6
STL7:45 amLambert-St Louis
8h 22m
1 stop
YOW5:07 pmOttawa
$309

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 March 23, 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

Cheapest round-trip

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

7:00 am-12:06 pm

1 stop6h 06m

Lambert-St Louis

Wed 5/6

1:05 pm-8:51 pm

1 stop6h 46m

$299

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 5/25

6:25 am-3:46 pm

1 stop10h 21m

Lambert-St Louis

Fri 5/29

6:00 am-1:59 pm

1 stop6h 59m

$304
Quickest round-trip

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Fri 6/5

7:00 am-12:06 pm

1 stop6h 06m

Lambert-St Louis

Sun 6/7

7:05 am-1:05 pm

1 stop5h 00m

$305

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

5:25 pm-9:13 pm

1 stop4h 48m

Lambert-St Louis

Wed 5/6

6:30 am-9:35 pm

1 stop14h 05m

$308

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

6:25 am-9:13 pm

1 stop15h 48m

Lambert-St Louis

Wed 5/6

7:45 am-9:35 pm

1 stop12h 50m

$309

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 4/15

9:15 am-3:25 pm

1 stop7h 10m

Lambert-St Louis

Wed 5/20

7:05 am-1:05 pm

1 stop5h 00m

$319

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/26

6:05 am-3:46 pm

2 stops10h 41m

Lambert-St Louis

Thu 5/28

6:00 am-2:17 pm

2 stops7h 17m

$362

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

2:00 pm-9:13 pm

2 stops8h 13m

Lambert-St Louis

Wed 5/6

6:30 am-5:07 pm

1 stop9h 37m

$370

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 5/5

2:00 pm-9:13 pm

2 stops8h 13m

Lambert-St Louis

Wed 5/6

7:45 am-5:07 pm

1 stop8h 22m

$371

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 4/15

6:00 am-12:22 pm

2 stops7h 22m

Lambert-St Louis

Wed 5/20

7:05 am-1:05 pm

1 stop5h 00m

$378

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 12 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 cheapest airline that flies from Ottawa to Lambert-St Louis?

United Airlines is the most popular carrier operating from Ottawa to Lambert-St Louis

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

6h 46m

Direct flights

None
The fastest flight from Ottawa to St. Louis takes 6h 46m
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 6h 46m.

  • 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 $343Free CancellationRating
7.1
10,834 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
Florissant
Maryland Heights
O'Fallon
Collinsville
St. Peters
Wentzville
Alton
Fenton
Farmington
Clayton
Festus
Edwardsville
Eureka
Litchfield
Shrewsbury
Grafton

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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