YOW - STL

$215 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 5/18. 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

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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Flights Deals

Cheap Flights from Ottawa to St. Louis

 
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.

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

KAYAK's recommended round-trip deals from the most popular airlines that fly from Ottawa to St. Louis.
Discover the best prices for you by selecting your travel dates on KAYAK.
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3:50 pm - 9:15 amYOW-STL
18h 25m1 stop
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5:45 pm - 5:06 pmSTL-YOW
22h 21m1 stop
$407
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Fri, May 30 - Sun, Jun 1
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4:25 pm - 11:53 pmYOW-STL
8h 28m1 stop
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5:47 pm - 5:06 pmSTL-YOW
22h 19m1 stop
$512
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Sat, Jun 14 - Sat, Jun 21
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4:25 pm - 11:53 pmYOW-STL
8h 28m1 stop
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7:29 pm - 6:45 amSTL-YOW
34h 16m2 stops
$538
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Sat, Jun 14 - Sat, Jun 21
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4:25 pm - 5:04 pmYOW-STL
25h 39m2 stops
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9:50 am - 12:22 amSTL-YOW
13h 32m3 stops
$565
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Sat, Jun 14 - Sat, Jun 21
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5:55 am - 5:04 pmYOW-STL
36h 09m3 stops
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9:50 am - 12:22 amSTL-YOW
13h 32m3 stops
$568
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Sat, Jun 14 - Sat, Jun 21
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5:55 am - 5:09 pmYOW-STL
12h 14m2 stops
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5:45 pm - 5:06 pmSTL-YOW
22h 21m1 stop
$587
Find Deal
Fri, May 30 - Sun, Jun 1
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5:55 am - 12:36 pmYOW-STL
7h 41m1 stop
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9:50 am - 12:22 amSTL-YOW
13h 32m3 stops
$588
Find Deal
Sat, Jun 14 - Sat, Jun 21
WestJet Logo
5:55 am - 8:49 pmYOW-STL
15h 54m2 stops
WestJet Logo
6:00 am - 12:22 amSTL-YOW
17h 22m2 stops
$617WestJet
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Fri, May 30 - Sun, Jun 1
United Airlines Logo
10:37 am - 2:56 pmYOW-STL
5h 19m1 stop
United Airlines Logo
8:05 am - 6:52 pmSTL-YOW
9h 47m2 stops
$659United Airlines
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Sat, Jun 14 - Sat, Jun 21
WestJet Logo
5:55 am - 1:19 pmYOW-STL
8h 24m2 stops
WestJet Logo
10:45 am - 12:22 amSTL-YOW
12h 37m2 stops
$701WestJet
Find Deal
Fri, May 30 - Sun, Jun 1
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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’s the cheapest day of the week to fly from Ottawa to St. Louis?

The average price of all round-trip flights from Ottawa to St. Louis clicked on KAYAK for each day over the last 12 months.

If your flying dates are flexible, you should consider flying to St. Louis on a Wednesday, as we generally find the cheapest rates on that day for this route. On the other hand, Monday is the most expensive day to fly from Ottawa to St. Louis. For your return ticket, we recommend flying on a Saturday and avoiding Mondays for the best deals.

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 $569 (return) on average. On the other hand, the most expensive months are August and December, where the average cost of round-trip tickets is $762 and $740 respectively.

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Good to know

Low seasonJune
High seasonJuly
Cheapest flight$215
Best time to beat the crowds with an average 7% drop in price.
Most popular time to fly with an average 1% increase in price.
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 $215 for a one-way ticket and $407 for a round-trip.

  • Do I need a passport to fly between Ottawa and St. Louis?

    Yes

  • 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.

  • 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. Booking your flights between Ottawa and STL can sometimes prove cheaper using this method.

  • 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.

Top airline 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.
7.0
Air CanadaOverall score based on 9245 reviews
7.0Comfort
7.3Boarding
6.3Food
7.8Crew
6.8Entertainment
Airline reviews

My flight got delayed 5 times and then got cancelled eventually, I had to get a hotel and uber and pay for food for an extra night without any plans. It was a horrible experience, instead of Air Canada, I was flying with United .

2.0 MediocreAnonymous, Apr 2025YYZ - IAD
Read more Air Canada reviews

My flight got delayed 5 times and then got cancelled eventually, I had to get a hotel and uber and pay for food for an extra night without any plans. It was a horrible experience, instead of Air Canada, I was flying with United .

I had a nice flight with free wifi. So I was able to message family members and stream music during my flight, which made the trip go by fast. I also enjoyed flying on there Airbus A220. The plane looked very new and it also got up to speed fast down the runway and didn't need much runway to get airborne.

They lost my checked in luggage, why do I pay for my cargo not arriving at the same destination as me?

Overall good experience. The flight from Toronto to Denver does not have entertainment - movies to watch.

Poor planning meant the plane was delayed an hour, then a thunder storm started and the ground staff couldn't work. Eventual arrival in Santiago was 3 hours late resulting in missed connections and the need to buy new tickets.

Ensure prepaid food arrangements are appropriately understood by flight crew of who purchased and who did not

All was fine. Weather was a bit stormy, but nothing kayak can do about that! 😊

I paid for a comfort class seat and was seated in economy.

The take off was delayed as we were told that the baggages had to be rearranged to balance the weight. I only took a carry-on and a personal item, but the overhead bin was extremely small, even a normal size carryon can’t fit it, so they had to check it in for free. The seat was really tight and no entertainment at all.

My plane was cancelled and had to be rebook for the evening was not happy.

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

Information on your arrival and departure airports

St. Louis (STL)
Ottawa (YOW)

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