C$ 228 Find Cheap Flights from St. Louis to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Ontario departing on 24/5. 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 Ontario

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

Cheap Flight Deals from St. Louis to Ontario (STL-CAON)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Ontario 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 St. Louis to Ontario

Recommended round-trip deals departing in the coming months from the most popular airlines that fly from St. Louis to Ontario.
Discover the best prices for you by selecting your travel dates on KAYAK.
 Logo
11:28 a.m. - 2:05 p.m.STL-YYZ
25h 37m1 stop
 Logo
6:30 a.m. - 10:33 a.m.YYZ-STL
29h 03m1 stop
C$ 469
Find Deal
Fri, 20 Jun - Sun, 22 Jun
 Logo
11:28 a.m. - 2:05 p.m.STL-YYZ
25h 37m1 stop
 Logo
6:30 a.m. - 10:33 a.m.YYZ-STL
29h 03m1 stop
C$ 483
Find Deal
Mon, 16 Jun - Thu, 19 Jun
Air Canada Logo
7:30 a.m. - 10:25 a.m.STL-YYZ
1h 55mdirect
Air Canada Logo
11:30 a.m. - 12:36 p.m.YYZ-STL
2h 06mdirect
C$ 641Air Canada
Find Deal
Fri, 13 Jun - Fri, 20 Jun
Air Canada Logo
7:30 a.m. - 10:25 a.m.STL-YYZ
1h 55mdirect
Air Canada Logo
11:30 a.m. - 12:36 p.m.YYZ-STL
2h 06mdirect
C$ 657Air Canada
Find Deal
Fri, 13 Jun - Fri, 20 Jun
Delta Logo
6:00 a.m. - 4:10 p.m.STL-YYZ
9h 10m1 stop
Delta Logo
6:15 a.m. - 3:08 p.m.YYZ-STL
9h 53m1 stop
C$ 663Delta
Find Deal
Tue, 27 May - Thu, 29 May
American Airlines Logo
5:12 a.m. - 4:44 p.m.STL-YYZ
10h 32m1 stop
American Airlines Logo
1:15 p.m. - 11:51 p.m.YYZ-STL
11h 36m1 stop
C$ 677American Airlines
Find Deal
Wed, 28 May - Fri, 30 May
Delta Logo
6:45 p.m. - 9:09 p.m.STL-YUL
25h 24m1 stop
Delta Logo
6:05 a.m. - 8:48 p.m.YUL-STL
15h 43m1 stop
C$ 682Delta
Find Deal
Thu, 29 May - Mon, 2 Jun
American Airlines Logo
1:38 p.m. - 11:15 p.m.STL-YYZ
8h 37m1 stop
American Airlines Logo
1:15 p.m. - 11:51 p.m.YYZ-STL
11h 36m1 stop
C$ 696American Airlines
Find Deal
Tue, 27 May - Tue, 3 Jun
United Airlines Logo
4:00 p.m. - 7:00 p.m.STL-YYZ
2h 00mdirect
United Airlines Logo
6:30 p.m. - 7:33 p.m.YYZ-STL
2h 03mdirect
C$ 738United Airlines
Find Deal
Sun, 24 Aug - Sun, 14 Sep
United Airlines Logo
5:00 a.m. - 1:47 p.m.STL-YYZ
7h 47m2 stops
United Airlines Logo
2:10 p.m. - 3:16 p.m.YYZ-STL
2h 06mdirect
C$ 764United Airlines
Find Deal
Fri, 4 Jul - Mon, 7 Jul
Useful Info

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

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

What is the cheapest St. Louis to Ontario flight route?

The cheapest price for flight routes found by users searching on KAYAK in the last 2 weeks for round-trip flights from St. Louis to Ontario.

The cheapest ticket to Ontario from St. Louis found in the last 72 hours was to Toronto, at C$ 283 round-trip. The most popular route is from St. Louis (STL) to Toronto Pearson Intl Airport (YYZ), and the cheapest round-trip airline ticket found on this route in the last 72 hours was C$ 283.

Can I save money by flying with a layover from St. Louis to Ontario?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of C$ 559, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Ontario, 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 St. Louis to Ontario is May, when tickets cost C$ 363 (return) on average. On the other hand, the most expensive months are March and June, when the average cost of round-trip tickets is C$ 807 and C$ 742 respectively.

What’s the cheapest day of the week to fly from St. Louis to Ontario?

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

If you are looking for a flight deal from St. Louis to Ontario, look for departures on Thursdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Ontario, Tuesday is the cheapest day to fly and Saturday is the most expensive.

How far in advance should I book a flight from St. Louis to Ontario?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Ontario, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below-average price on the flight from St. Louis to Ontario, you should book around 5 weeks before departure. For the absolute cheapest price, our data suggests you should book 23 weeks before departure.


Good to know

Low seasonFebruary
High seasonMay
Cheapest flightC$ 228
Best time to beat the crowds (13% less expensive on average)
Most popular time to fly and prices are also 35% lower on average.
Flight from St. Louis to Toronto

FAQs - booking Ontario flights

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

    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 St. Louis to Ontario.

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

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

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

    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 from St. Louis to Ontario with an airline and back with another airline.

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

    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 from St. Louis to Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Ontario?

    The cheapest time of day to fly to Ontario is generally in the afternoon, when round-trip flights cost C$ 224 on average. Morning departures are around 15% more expensive than evening flights, on average. The most expensive time of day to fly to Ontario is generally in the morning, which is peak travel time and where the average cost of a ticket is C$ 671.

Top airline flying from St. Louis to Ontario

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Ontario. 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 St. Louis to Ontario? 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 9244 reviews
7.0Comfort
7.3Boarding
6.8Entertainment
6.3Food
7.8Crew
Airline reviews

2.5 hour delay sitting in the plane on the tarmac, you tell me how the experience was

2.0 MediocreKamini, Apr 2025ORD - YYZ
Read more Air Canada reviews

2.5 hour delay sitting in the plane on the tarmac, you tell me how the experience was

I hope these comments will find their way to AC customer experience team. Me and my spouse 50 years of aged coming back from 7 days perfect vacation... While boarding in FLL flight AC1621, one of the boarding agents (tall aged african american) man literelly yeld at my wife during the picture talking process. MAM ! STEP !! BACK !!! We are not illegal immegrants beying deported, nor are we in the millitary. We are customers returning home. This was unacceptable. While boarding in YYZ flight AC1154, one of the boarding agents (tall aged caucasian) man criticied with several complesant remarks my passport condition saying that I could not travel intl with it due to stain, decoloration, and BLOOD. My passport does not have blood on it! Yes it might be in less than perfect condition, but their are ways to talk to customer that does not imply not allow a boarding agent to be angry fathery like, or a custom agent looking at a suspicious individual. Both experience were less than acceptable for might I remind you a paying CUSTOMER returning home.

This flight didn't happen for me because of overbooking.

Terrible experience, flight was delayed both ways. Limited compensation for the 5+ hour delay. Will not be flying Air Canada Rouge, and don’t recommend you do either.

The boarding was relatively quick, the crew welcoming and flight uneventful. The omission of meals on all airlines is unacceptable especially when the flight is during a mealtime such as this one, (lunchtime), is unacceptable.

Everything was simple and easy. The lady at the gate was super friendly, I wish I had her name to share. She's a little older, dark-haired. You can tell she likes her job and would be a great influence on any young people training with her.

No Charging ports for personal electronics, which were required to use wifi entertainment.

Rushed, the boarding was a great deal like a Chinese fire drill.

it was red eye flight, it was ok, there was beverage service, thats it i didnt care much as i wanted to sleep

Everything went smoothly. I appreciate the selection of free movies.

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

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