Latest deals
Insights
When to book
FAQs
Reviews
Price Alerts

Cheap flights from Ottawa to St. Louis from C$ 313

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 13/9. 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

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names, great deals

Big names, great deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

Free Wi-Fi? Early arrival? Instantly customize your results

Trusted and free

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from Ottawa to St. Louis

Cheap round-trip flights

Logo
3:50 p.m. - 9:40 a.m.YOW-STL
18h 50m1 stop
Logo
5:40 p.m. - 5:06 p.m.STL-YOW
22h 26m1 stop
C$ 666
Find Deal
Wed, 13 Aug - Thu, 14 Aug
Logo
4:25 p.m. - 1:32 p.m.YOW-STL
22h 07m2 stops
Logo
2:30 p.m. - 5:20 p.m.STL-YOW
25h 50m3 stops
C$ 720
Find Deal
Thu, 21 Aug - Mon, 25 Aug
Logo
4:25 p.m. - 1:32 p.m.YOW-STL
22h 07m2 stops
Logo
3:16 p.m. - 5:06 p.m.STL-YOW
24h 50m1 stop
C$ 752
Find Deal
Thu, 21 Aug - Mon, 25 Aug
Logo
12:35 p.m. - 1:32 p.m.YOW-STL
25h 57m3 stops
Logo
2:30 p.m. - 5:20 p.m.STL-YOW
25h 50m3 stops
C$ 764
Find Deal
Thu, 21 Aug - Mon, 25 Aug
United Airlines Logo
5:25 p.m. - 3:44 p.m.YOW-STL
23h 19m1 stop
United Airlines Logo
7:04 p.m. - 5:06 p.m.STL-YOW
21h 02m1 stop
C$ 766United Airlines
Find Deal
Tue, 26 Aug - Tue, 2 Sep
United Airlines Logo
7:29 p.m. - 10:46 a.m.YOW-STL
16h 17m2 stops
United Airlines Logo
7:04 p.m. - 2:26 p.m.STL-YOW
18h 22m2 stops
C$ 786United Airlines
Find Deal
Tue, 26 Aug - Tue, 2 Sep
Air Canada Logo
2:25 p.m. - 8:00 p.m.YOW-STL
6h 35m1 stop
Air Canada Logo
9:15 a.m. - 5:04 p.m.STL-YOW
6h 49m1 stop
C$ 843Air Canada
Find Deal
Tue, 26 Aug - Tue, 2 Sep
United Airlines Logo
5:09 p.m. - 10:43 p.m.YOW-STL
6h 34m1 stop
United Airlines Logo
11:05 a.m. - 9:18 p.m.STL-YOW
9h 13m1 stop
C$ 861United Airlines
Find Deal
Mon, 22 Dec - Mon, 5 Jan
WestJet Logo
5:55 a.m. - 1:20 p.m.YOW-STL
8h 25m2 stops
WestJet Logo
3:42 p.m. - 12:22 a.m.STL-YOW
7h 40m2 stops
C$ 903WestJet
Find Deal
Thu, 21 Aug - Mon, 25 Aug
WestJet Logo
5:55 a.m. - 11:14 p.m.YOW-STL
18h 19m2 stops
WestJet Logo
5:11 p.m. - 12:22 a.m.STL-YOW
30h 11m2 stops
C$ 1,037WestJet
Find Deal
Mon, 18 Aug - Sun, 31 Aug

United Airlines flights from Ottawa to St. Louis

Our best United Airlines deals on Ottawa to St. Louis flight tickets
United Airlines
26 Aug
YOW5:25 p.m.Ottawa
23h 19m
1 stop
STL3:44 p.m.Lambert-St Louis
2 Sep
STL7:04 p.m.Lambert-St Louis
21h 02m
1 stop
YOW5:06 p.m.Ottawa
C$ 766
Find similar
United Airlines
26 Aug
YOW7:29 p.m.Ottawa
16h 17m
2 stops
STL10:46 a.m.Lambert-St Louis
2 Sep
STL7:04 p.m.Lambert-St Louis
18h 22m
2 stops
YOW2:26 p.m.Ottawa
C$ 786
Find similar
United Airlines
22 Dec
YOW5:09 p.m.Ottawa
6h 34m
1 stop
STL10:43 p.m.Lambert-St Louis
5 Jan
STL11:05 a.m.Lambert-St Louis
9h 13m
1 stop
YOW9:18 p.m.Ottawa
C$ 861
Find similar

WestJet flights from Ottawa to St. Louis

Our best WestJet deals on Ottawa to St. Louis flight tickets
WestJet
21 Aug
YOW5:55 a.m.Ottawa
8h 25m
2 stops
STL1:20 p.m.Lambert-St Louis
25 Aug
STL3:42 p.m.Lambert-St Louis
7h 40m
2 stops
YOW12:22 a.m.Ottawa
C$ 903
Find similar
WestJet
18 Aug
YOW5:55 a.m.Ottawa
18h 19m
2 stops
STL11:14 p.m.Lambert-St Louis
31 Aug
STL5:11 p.m.Lambert-St Louis
30h 11m
2 stops
YOW12:22 a.m.Ottawa
C$ 1,037
Find similar
WestJet
13 Aug
YOW5:55 a.m.Ottawa
28h 37m
2 stops
STL9:32 a.m.Lambert-St Louis
14 Aug
STL1:26 p.m.Lambert-St Louis
9h 56m
2 stops
YOW12:22 a.m.Ottawa
C$ 1,077
Find similar

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 96,600 searches. Data last updated 31 July 2025.
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

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Wed 13/8

3:50 p.m.-9:40 a.m.

1 stop18h 50m

Lambert-St Louis

Thu 14/8

5:40 p.m.-5:06 p.m.

1 stop22h 26m

C$ 666

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 21/8

4:25 p.m.-1:32 p.m.

2 stops22h 07m

Lambert-St Louis

Mon 25/8

2:30 p.m.-5:20 p.m.

3 stops25h 50m

C$ 720

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 21/8

4:25 p.m.-1:32 p.m.

2 stops22h 07m

Lambert-St Louis

Mon 25/8

3:16 p.m.-5:06 p.m.

1 stop24h 50m

C$ 752

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 21/8

12:35 p.m.-1:32 p.m.

3 stops25h 57m

Lambert-St Louis

Mon 25/8

2:30 p.m.-5:20 p.m.

3 stops25h 50m

C$ 764

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 26/8

5:25 p.m.-3:44 p.m.

1 stop23h 19m

Lambert-St Louis

Tue 2/9

7:04 p.m.-5:06 p.m.

1 stop21h 02m

C$ 766

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 26/8

7:29 p.m.-10:46 a.m.

2 stops16h 17m

Lambert-St Louis

Tue 2/9

7:04 p.m.-2:26 p.m.

2 stops18h 22m

C$ 786

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Tue 26/8

2:25 p.m.-8:00 p.m.

1 stop6h 35m

Lambert-St Louis

Tue 2/9

9:15 a.m.-5:04 p.m.

1 stop6h 49m

C$ 843

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 22/12

5:09 p.m.-10:43 p.m.

1 stop6h 34m

Lambert-St Louis

Mon 5/1

11:05 a.m.-9:18 p.m.

1 stop9h 13m

C$ 861

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 21/8

5:55 a.m.-1:20 p.m.

2 stops8h 25m

Lambert-St Louis

Mon 25/8

3:42 p.m.-12:22 a.m.

2 stops7h 40m

C$ 903

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Mon 18/8

5:55 a.m.-11:14 p.m.

2 stops18h 19m

Lambert-St Louis

Sun 31/8

5:11 p.m.-12:22 a.m.

2 stops30h 11m

C$ 1,037

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 15 resultsSorted by cheapest first
1
2

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 month to fly to St. Louis?

The month of September is, on average, the cheapest month to fly to St. Louis from Ottawa, with most prices found around C$ 705. If you don’t want to visit St. Louis in September, then you should wait until April to fly from Ottawa, when ticket prices are also cheap, with an average price of C$ 808.

What is the cheapest day to depart on your flight to St. Louis?

Our data shows that Monday is the least expensive day to fly to St. Louis. Tickets to fly out on this day can be as low as C$ 786. The most expensive day to fly to St. Louis is Thursday, with ticket prices averaging around C$ 1,021.

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

Best price found

C$ 313

Fastest flight time

6h 34m

Direct flights

None

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Ottawa in the past 72 hours is C$ 313. The best round-trip flight deal from Ottawa to St. Louis found on momondo in the last 72 hours is C$ 666.
The fastest flight from Ottawa to St. Louis takes 6h 34m
There are no direct flights from Ottawa to St. Louis. Popular non-direct route for this connection is Ottawa Airport - Lambert-St Louis Airport.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
Search flight deals

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

    A flight from Ottawa to Lambert-St Louis will travel around 1411.6 km. 6h 34m is a normal flight duration for this route.

  • 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?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to 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 C$ 765Free CancellationRating
7.1
9,851 reviews
Search Air Canada flights

Travelling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
Chesterfield
Collinsville
Litchfield

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Ottawa to St. Louis for you.

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

All flight searches from Ottawa to St. Louis on momondo can be filtered to show those which offer flexible booking policies.

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?

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

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.
1 adult
Tue 5/8
Tue 12/8
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States