YOW - STL

C$ 249 Find Cheap Flights from Ottawa to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ottawa to St. Louis departing on 15/12. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ottawa to St. Louis, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ottawa to St. Louis, as well as popular online travel agencies
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Flight Deals

Cheap Flights from Ottawa to St. Louis (YOW-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ottawa to St. Louis that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ottawa to St. Louis

Tue, 3 Feb - Wed, 4 Feb
Air Canada Logo
10:20 a.m. - 3:29 p.m.YOW-STL
6h 09m1 stop
Air Canada Logo
4:05 p.m. - 11:08 p.m.STL-YOW
6h 03m1 stop
C$ 415Air Canada
Find Deal
Fri, 23 Jan - Sun, 25 Jan
United Airlines Logo
7:27 p.m. - 10:13 a.m.YOW-STL
15h 46m1 stop
United Airlines Logo
6:30 a.m. - 2:27 p.m.STL-YOW
6h 57m2 stops
C$ 420United Airlines
Find Deal
Fri, 23 Jan - Sun, 25 Jan
United Airlines Logo
2:15 p.m. - 10:58 p.m.YOW-STL
9h 43m2 stops
United Airlines Logo
8:05 a.m. - 9:18 p.m.STL-YOW
12h 13m1 stop
C$ 422United Airlines
Find Deal
Tue, 7 Apr - Wed, 8 Apr
United Airlines Logo
6:52 a.m. - 12:20 p.m.YOW-STL
6h 28m1 stop
United Airlines Logo
6:30 a.m. - 12:41 p.m.STL-YOW
5h 11m1 stop
C$ 423United Airlines
Find Deal
Fri, 23 Jan - Sun, 25 Jan
United Airlines Logo
2:15 p.m. - 10:58 p.m.YOW-STL
9h 43m2 stops
United Airlines Logo
6:30 a.m. - 2:30 p.m.STL-YOW
7h 00m2 stops
C$ 496United Airlines
Find Deal
Tue, 7 Apr - Wed, 8 Apr
Air Canada Logo
5:45 a.m. - 3:21 p.m.YOW-STL
10h 36m2 stops
Air Canada Logo
4:05 p.m. - 11:04 p.m.STL-YOW
5h 59m1 stop
C$ 506Air Canada
Find Deal
Wed, 4 Feb - Thu, 5 Feb
Air Canada Logo
10:20 a.m. - 3:29 p.m.YOW-STL
6h 09m1 stop
Air Canada Logo
4:05 p.m. - 11:08 p.m.STL-YOW
6h 03m1 stop
C$ 595Air Canada
Find Deal
Tue, 23 Dec - Tue, 30 Dec
Multiple Airlines Logo
4:20 p.m. - 10:33 p.m.YOW-STL
31h 13m1 stop
Multiple Airlines Logo
11:51 a.m. - 12:25 a.m.STL-YOW
11h 34m1 stop
C$ 658Multiple Airlines
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Thu, 27 Nov - Sun, 30 Nov
American Airlines Logo
6:45 a.m. - 4:25 p.m.YOW-STL
10h 40m2 stops
American Airlines Logo
6:00 a.m. - 4:49 p.m.STL-YOW
9h 49m2 stops
C$ 787American Airlines
Find Deal
Tue, 23 Dec - Tue, 30 Dec
American Airlines Logo
9:10 a.m. - 11:52 p.m.YOW-STL
15h 42m2 stops
American Airlines Logo
8:01 p.m. - 4:51 p.m.STL-YOW
19h 50m2 stops
C$ 888American Airlines
Find Deal

Everything you should know

Top airlines
Air Canada
Cheapest • from C$ 415 (round-trip)
United Airlines
Best reviews • 7.4 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
September
Cheapest • 18% price drop
May
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest round-trip
C$ 415
Overall average: C$ 884
Air Canada
Tue 3/2Wed 4/2
YOW - STL • 1 stop
Cheapest one-way flights
C$ 249
United Airlines
Mon 15/12
YOW - STL • 2 stops
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KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to St. Louis!
Booking Insights

KAYAK's insights & trends for Ottawa to St. Louis flights

Get data-powered insights and trends into flights from Ottawa to St. Louis to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Ottawa to St. Louis?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ottawa to St. Louis, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ottawa to St. Louis is September, where tickets cost C$ 720 (return) on average. On the other hand, the most expensive months are December and August, where the average cost of round-trip tickets is C$ 1,036 and C$ 980 respectively.

Good to know

Low seasonJune
Cheapest flightC$ 249
Best time to beat the crowds (0% less expensive on average)
Most popular time to fly (9% more expensive on average)
Flight from Ottawa to St. Louis

When to book flights from Ottawa to St. Louis

Are your dates flexible? Find out the best times to travel from Ottawa to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Ottawa to St. Louis

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

    In the last 3 days, the lowest price for a flight from Ottawa to St. Louis was C$ 249 for a one-way ticket and C$ 415 for a round-trip.

  • Which airports will I be using when flying from Ottawa to St. Louis?

    Ottawa airport is called Ottawa and the only airport in St. Louis is Lambert-St Louis.

  • Which aircraft models fly most regularly from Ottawa to St. Louis?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Ottawa to St. Louis?

    Star Alliance is the only airline alliance operating flights between Ottawa and St. Louis.

  • Which is the best airline for flights from Ottawa to St. Louis, United Airlines or Air Canada?

    The two airlines most popular with KAYAK users for flights from Ottawa to St. Louis are United Airlines and Air Canada. With an average price for the route of C$ 862 and an overall rating of 7.4, United Airlines is the most popular choice. Air Canada is also a great choice for the route, with an average price of C$ 859 and an overall rating of 7.1.

  • How does KAYAK find such low prices on flights from Ottawa to St. Louis?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ottawa to St. Louis.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ottawa to St. Louis?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Ottawa is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ottawa to St. Louis?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Ottawa with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ottawa to St. Louis?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Ottawa up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from Ottawa to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Ottawa to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Ottawa to St. Louis? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 8995 reviews
6.6Food
7.1Entertainment
7.7Boarding
7.3Comfort
8.1Crew
Airline reviews

Lately I like the planes have been exceptionally filthy. There’s lines of dust and dirt all across the ceiling in the vents, and the cracks in between the seats are literally full of food. It’s definitely not the quality of service that I was used to with United. I’m also very disappointed with the Wi-Fi! All I wanna do is knock out a few work jobs while I’m trapped in my seat And it spools so bad. They did provide me with a refund, but the process of getting that refund is so complicated. It’s unfortunate.

4.0 OkayNicole, Oct 2025IAH - MCI
Read more United Airlines reviews

Lately I like the planes have been exceptionally filthy. There’s lines of dust and dirt all across the ceiling in the vents, and the cracks in between the seats are literally full of food. It’s definitely not the quality of service that I was used to with United. I’m also very disappointed with the Wi-Fi! All I wanna do is knock out a few work jobs while I’m trapped in my seat And it spools so bad. They did provide me with a refund, but the process of getting that refund is so complicated. It’s unfortunate.

Excellent flight. Smooth, efficient boarding. Quick flight. Arrived early at STL.

The food quality sucks. One must starve if they do not eat flesh Or wheat based products Some variety would be expected. The trivial amount of snacks and or food is inhumane

We Left Calgary 1/2 hour late and that made for a tight connection in Denver. After arriving everything was done to help us make our connection. That was a great effort. Thank You United

Efficient all round, very good crew. Short flight so the food, of course, was just snacks

Overall, it was good. I was seating next to a wonderful lady and did not notice how time flew. Thanks

My flight was delayed about 1 1/2 hours in Chicago, but other then that it was a good flight.

The experience was great, the crew was very polite and hospitable. I will definitely make if my go to airlines.

It was all good flight was on time, service was good I enjoyed a few movies and everything was smooth

Efficient, calm when things were delayed and kept us regularly informed of what was happening.

The free Wi-fi for Aeroplan members was a great touch. The time passed quickly. I found the seats seemed a little closer together than I remember. Not Air Canada's fault, but we were about 20 minutes late landing because the airport was too busy. We had to circle around for a while. The boarding and disembarking went very smoothly.

Extremely turbulent landing. Crew was friendly and plane comfortable. Airport and US pre clearance was understaffed

The airplane is way too tight, you can hardly enter into your row to sit.. more like kids seats than adults.

Wifi was great. Kind air crew and comfortable seating. Also liked the entertainment options.

First message when all on board was that we didnt have a pilot, then they found one, then it was something about the bridge something not working, they will either fix or do manually. Flight of course was leaving late with all the cruise guests worrying about making it to their ship in time. Then only some luggage made it off the ship. Around 15 to 20 people waiting. 45 min later arrived except mine. I asked the rep at the luggage conveyor, he asked me my name. Then said it was not picked up with the first batch so they put it in a room. I was going to take public transport but now worried about time so took a taxi that cost me $65 USD

The flight was very smooth and good. Boarding was fast, but the staff was just decently friendly.

Air Canada flight staff are in contact negotiations and they are less than happy and it show. The process of self checking baggage is less than desirable with lack of support staff to help

A sandwich and a drink would have been better thank a snack bar...

Flying with Air Canada is still better than the discount airlines like Flair. The seats are more comfortable and the on-board entertainment is better, with each seat having a built in screen and lots of content to watch. Onboard WIFI is also great to have, as well as plugs for charging. I think passengers in general are getting better at not bringing too much luggage onboard, and Air Canada is better at managing this without customers feeling like they are being taken advantage of with extra fees. I have travelled on different airlines and all seem to be loading faster, with fewer people bringing both a carry on and a personal item. Now I just bring one item and it fits under the seat so I don't need to worry about finding a place in the overhead bins. Overall, across the industry, asking customers to pay for carry on baggage is fair because it allows customers to only pay for what they need, and it helps to keep the planes on time. Kudos to Air Canada for its approach - the desired result is achieved without customers feeling that they are being surprised and caught with unexpected extra fees.

I liked the behaviour of the crew members.The flight was good.

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

Information on your arrival and departure airports

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