HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
St. Louis

$247+ Cheap flights from Ottawa (YOW) to St. Louis (STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/2. Fares are subject to change and may not be available on all flights or dates of travel.
YOW — STL
ago. 25 — sep. 11
lun. 8/25
lun. 9/1
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ottawa to St. Louis with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Ottawa to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Ottawa (YOW) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated agosto 20, 2025.

Round-trip from

$405
(Kiwi.com)

One-way from

$247
(Kiwi.com)

Popular in

December

Cheapest in

September

Average price

$709
From Ottawa to Lambert-St Louis
Search Deals
One-way flight from Ottawa to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($42 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 2025
Search Deals

Find flight deals from Ottawa to St. Louis

Cheapest flights from Ottawa to St. Louis
Explore the most affordable flight options available from Ottawa to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on agosto 20, 2025.

This Kiwi.com deal was found by Cheapflights users on 8/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 10/43:50 pmYOW - STL
1 stop19h 12mMultiple Airlines
sáb. 10/117:00 pmSTL - YOW
2 stops28h 22mMultiple Airlines
Deal found 8/20$405
This United Airlines deal was found by Cheapflights users on 8/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 10/410:25 amYOW - STL
2 stops13h 10mUnited Airlines
sáb. 10/115:28 pmSTL - YOW
2 stops22h 36mUnited Airlines
Deal found 8/20$509
This United Airlines deal was found by Cheapflights users on 8/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/225:09 pmYOW - STL
1 stop5h 34mUnited Airlines
sáb. 1/36:35 pmSTL - YOW
2 stops17h 57mUnited Airlines
Deal found 8/17$622
This Air Canada deal was found by Cheapflights users on 8/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 8/242:25 pmYOW - STL
1 stop6h 35mAir Canada
dom. 8/318:10 amSTL - YOW
1 stop4h 54mAir Canada
Deal found 8/18$929
This United deal was found by Cheapflights users on 8/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 8/246:33 amYOW - STL
1 stop9h 00mMultiple Airlines
dom. 8/3112:35 pmSTL - YOW
2 stops8h 30mMultiple Airlines
Deal found 8/18$1,059
This FlightHub deal was found by Cheapflights users on 8/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 8/247:15 pmYOW - STL
2 stops24h 52mWestJet
dom. 8/3110:45 amSTL - YOW
2 stops36h 37mWestJet
Deal found 8/18$1,116

Cheapflights 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, Cheapflights users made 2,558,603 searches. Data last updated agosto 20, 2025.
Use the filters below to find and compare flights from Ottawa to St. Louis that are best for you.

Fly from

Ottawa

Fly to

St. Louis

Route

Depart

Return

Price

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 10/4

3:50 pm-10:02 am

1 stop19h 12m

Lambert-St Louis

sáb. 10/11

7:00 pm-12:22 am

2 stops28h 22m

$405

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

sáb. 10/4

10:25 am-10:35 pm

2 stops13h 10m

Lambert-St Louis

sáb. 10/11

5:28 pm-5:04 pm

2 stops22h 36m

$509

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

lun. 12/22

6:00 am-5:54 pm

2 stops12h 54m

Lambert-St Louis

sáb. 1/3

6:35 pm-1:32 pm

2 stops17h 57m

$622

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

jue. 10/2

4:25 pm-8:37 pm

1 stop29h 12m

$247

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

jue. 9/18

5:15 pm-9:06 am

3 stops40h 51m

$257

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

vie. 9/19

4:25 pm-9:40 am

2 stops42h 15m

$258

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

jue. 9/18

6:33 am-3:44 pm

1 stop10h 11m

$307

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

mar. 8/26

7:00 am-9:11 am

3 stops51h 11m

$341

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

vie. 9/19

11:55 am-3:18 pm

1 stop4h 23m

$345

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/18

Best time to book a flight from Ottawa to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ottawa with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Ottawa to St. Louis

What is the cheapest month to book a flight from Ottawa to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $311). Flying from Ottawa to St. Louis in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost to fly round-trip from Ottawa to St. Louis?

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated agosto 20, 2025.
Read through reviews of airlines operating flights from Ottawa to St. Louis, such as Air Canada. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Air Canada
7.1
Good
10,000 reviews

Overall

7.1

Comfort

7.1

Entertainment

6.8

Crew

7.8

Food

6.3

Boarding

7.3

Reviews

1 / 20
8.0
Excellent

Jadi-Ann,Jun 2025

YYZ - KIN

The flight was smooth with minor turbulence. The staff was courteous. Since I have an aeroplan account I was able to use the inflight wifi. I wanted extra space and the window seat and I had to pay for that. At first, I was okay with that, however, I felt that it was the same distance between for everyone. Maybe I could be wrong.
Air Canada
7.1
Good
10,000 reviews
Air Canada
7.1
Good
10,000 reviews

Overall

7.1

Comfort

7.1

Entertainment

6.8

Crew

7.8

Food

6.3

Boarding

7.3

Reviews

1 / 20
8.0
Excellent

Jadi-Ann,Jun 2025

YYZ - KIN

The flight was smooth with minor turbulence. The staff was courteous. Since I have an aeroplan account I was able to use the inflight wifi. I wanted extra space and the window seat and I had to pay for that. At first, I was okay with that, however, I felt that it was the same distance between for everyone. Maybe I could be wrong.

Related info for your journey

Find useful and relevant information for your journey from Ottawa to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Ottawa to St. Louis?

    Departing from Ottawa to St. Louis will take you 13h 10m. The distance from Ottawa to St. Louis is about 878 mi.

  • What is the cheapest airline to fly from Ottawa to St. Louis round-trip?

    Our cheapest airline available from Ottawa to St. Louis is Air Canada. Our recent data shows that you can find tickets from as low as $511 on this airline. You may be able to fly from Ottawa to St. Louis for 20% less than the average price by searching for this airline.

  • Can I find deals for flights from Ottawa to St. Louis that include hotel bookings?

    Yes. In addition to deals on Ottawa to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ottawa to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ottawa to St. Louis.

  • Can I find deals for business class flights from Ottawa to St. Louis?

    Yes. Cheapflights offers flight deals from Ottawa to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Ottawa to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Ottawa to St. Louis (average of $311). Flying from Ottawa to St. Louis in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
St. Peters
Glencoe
Alton
Chesterfield
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top airline flying from Ottawa to St. Louis

Discover the top airline that operate flights from Ottawa to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated agosto 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$511Average$677FlexibilityNo cancel feeOn-time67%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.