HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$82+ Cheap flights from St. Louis (STL) to Ontario

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 1/22. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YYZ
Dec 24 — Dec 311
Tue 12/24
Tue 12/31
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from St. Louis to Ontario 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 St. Louis to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Ontario (CAON). 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 December 19, 2024.

Round-trip from

$259
(Kiwi.com)

One-way from

$82
(Kiwi.com)
From Lambert-St Louis to Ontario
Search Deals
One-way flight from Lambert-St Louis to Ontario
Search Deals

Find flight deals from St. Louis to Ontario

Cheapest flights from St. Louis to Ontario
Explore the most affordable flight options available from St. Louis to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 19, 2024.

This Kiwi.com deal was found by Cheapflights users on 12/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/243:53 pmSTL - YYZ
1 stop18h 52mMultiple Airlines
Tue 12/317:05 amYYZ - STL
1 stop9h 16mMultiple Airlines
Deal found 12/17$456
This Air Canada deal was found by Cheapflights users on 12/17. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/285:27 pmSTL - YYZ
1 stop5h 32mAir Canada
Tue 12/311:50 pmYYZ - STL
Nonstop2h 16mAir Canada
Deal found 12/17$776
This United Airlines deal was found by Cheapflights users on 12/18. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/258:00 amSTL - YYZ
1 stop14h 59mUnited Airlines
Wed 1/11:50 pmYYZ - STL
Nonstop2h 16mUnited Airlines
Deal found 12/18$827
This Delta deal was found by Cheapflights users on 12/17. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/276:29 amSTL - YYZ
1 stop3h 53mDelta
Sat 12/285:15 pmYYZ - STL
1 stop5h 28mDelta
Deal found 12/17$834
This American Airlines deal was found by Cheapflights users on 12/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2611:42 amSTL - YYZ
1 stop4h 58mAmerican Airlines
Sat 12/285:15 pmYYZ - STL
1 stop5h 33mAmerican Airlines
Deal found 12/18$964
This American Airlines deal was found by Cheapflights users on 12/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/256:30 amSTL - YUL
1 stop4h 50mAmerican Airlines
Sun 1/57:13 amYUL - STL
1 stop7h 24mAmerican Airlines
Deal found 12/18$997
This Kiwi.com deal was found by Cheapflights users on 12/17. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/255:55 pmSTL - YYZ
1 stop3h 46mWestJet
Fri 12/272:11 pmYYZ - STL
1 stop3h 48mWestJet
Deal found 12/17$1,011
This United deal was found by Cheapflights users on 12/18. 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.
Wed 12/256:25 amSTL - YUL
2 stops10h 20mUnited Airlines
Sun 1/56:10 pmYUL - STL
2 stops22h 37mUnited Airlines
Deal found 12/18$1,105
This Justfly.com deal was found by Cheapflights users on 12/19. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/196:04 amSTL - YOW
2 stops22h 29mWestJet
Fri 12/275:55 amYOW - STL
2 stops12h 04mWestJet
Deal found 12/19$1,327
This Air Canada deal was found by Cheapflights users on 12/18. 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.
Thu 12/1911:30 amSTL - YOW
1 stop8h 54mAir Canada
Fri 12/2710:05 amYOW - STL
1 stop6h 01mAir Canada
Deal found 12/18$1,345
This United deal was found by Cheapflights users on 12/19. 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.
Thu 12/196:25 amSTL - YOW
2 stops8h 51mUnited Airlines
Fri 12/276:20 amYOW - STL
1 stop7h 06mUnited Airlines
Deal found 12/19$1,359

Find flights from St. Louis to Ontario within your budget

Customize your flight search to find flights from St. Louis to Ontario 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 December 19, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 1/15

5:05 pm-9:54 am

1 stop15h 49m

Toronto Pearson Intl

Tue 1/21

7:00 pm-11:31 pm

1 stop29h 31m

$259

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Thu 1/16

4:28 pm-5:35 pm

1 stop24h 07m

Montreal Pierre Elliott Trudeau Intl

Thu 1/23

10:00 am-11:31 pm

2 stops14h 31m

$346

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 1/8

6:05 am-4:11 pm

1 stop9h 06m

Toronto Pearson Intl

Wed 1/22

5:05 pm-8:58 am

1 stop16h 53m

$441

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 1/8

5:40 am-5:35 pm

1 stop10h 55m

Toronto Pearson Intl

Fri 1/10

7:00 am-2:58 pm

1 stop8h 58m

$492

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 1/7

2:49 pm-3:05 pm

1 stop23h 16m

Toronto Pearson Intl

Mon 1/13

4:20 pm-1:53 pm

1 stop22h 33m

$496

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 1/7

9:44 am-7:45 pm

1 stop9h 01m

Toronto Pearson Intl

Wed 1/8

6:52 am-2:14 pm

1 stop8h 22m

$517

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Wed 1/15

6:05 am-4:22 pm

1 stop9h 17m

Montreal Pierre Elliott Trudeau Intl

Wed 1/22

11:20 am-9:06 pm

1 stop10h 46m

$518

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Wed 1/8

2:15 pm-1:35 pm

1 stop22h 20m

Montreal Pierre Elliott Trudeau Intl

Thu 1/9

5:35 pm-11:32 am

1 stop18h 57m

$524

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 1/16

3:50 pm-6:45 pm

Nonstop1h 55m

Toronto Pearson Intl

Sun 1/19

1:50 pm-3:06 pm

Nonstop2h 16m

$550

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Sat 1/25

8:00 am-7:57 pm

2 stops10h 57m

Montreal Pierre Elliott Trudeau Intl

Fri 1/31

8:35 am-5:36 pm

2 stops10h 01m

$691

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/17

Showing 1-10 of 21 results
1
2
3

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

Have a flexible travel schedule? Discover the best time to fly to Ontario from St. Louis 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.

Travel insights for flights from St. Louis to Ontario

Get recent, data-driven insights about flights from St. Louis to Ontario including ideal travel times, pricing trends, and more.

What is the cheapest month to book a flight from St. Louis to Region of Ontario?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Region of Ontario (average of $243). Flying from St. Louis to Region of Ontario in July is currently the most expensive (average of $359). 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.

What is the cheapest time of day to fly from STL to ON?

Find hourly flight availability from St. Louis to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 19, 2024.

When flying from St. Louis to Region of Ontario, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from St. Louis to Region of Ontario

Explore weekly flight availability from St. Louis to Ontario. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated December 19, 2024.

The most flights from STL to CAON are scheduled on a Monday (2 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Region of Ontario ranges from 2.0 - 3.3 inches per month. June is typically the wettest month, when rainfall can reach 3.3 in. February is typically the driest time to visit Region of Ontario when rainfall is around 2.0 in.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Region of Ontario, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 69.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 21.2 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated December 19, 2024.
Peruse reviews from past customers who have flown with American Airlines, United Airlines and Air Canada from St. Louis to Ontario to help guide your decision. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

Alaska Airlines
8.0
Very good
9,552 reviews
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

Delta
8.0
Very good
8,600 reviews
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

United Airlines
7.4
Good
9,048 reviews
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

WestJet
7.3
Good
2,819 reviews
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,552 reviews

Boarding

8.2

Entertainment

7.1

Comfort

7.9

Crew

8.5

Food

7.2

Overall

8.0

Reviews

1 / 10

Things were good, crew was good. It was just the flight itself was very rough. Lots of turbulence, probably one of the shakiest flights I've been on. Kids throwing up, kids crying everywhere because of it.

Related info for your journey

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

  • What airport do you fly from for flights from St. Louis to Ontario?

    Lambert-St Louis (STL) is the airport you will fly out of if you book a flight from St. Louis to Ontario. It is only a 12.7 mi journey to Lambert-St Louis (STL) from St. Louis’s city center.

  • What are the cheapest airlines to fly from St. Louis to Region of Ontario one-way?

    One-way options have recently been found by users for as low as $283 on United Airlines. Other airlines that offer cheap prices include Air Canada from $285 and WestJet from $333 one-way.

  • What are the most popular routes from St. Louis to Region of Ontario?

    When deciding which route to take from St. Louis to Region of Ontario consider Lambert-St Louis - Toronto Pearson Intl, Lambert-St Louis - Montreal Pierre Elliott Trudeau Intl or Lambert-St Louis - Ottawa as they are the most popular.

  • What are the most reliable airlines from St. Louis to Region of Ontario?

    No one likes to see their flight delayed. When booking a flight from St. Louis to Region of Ontario consider choosing Air Canada (90%), Jazz (90%) or United Airlines (90%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from St. Louis to Region of Ontario?

    Looking for the cheapest flight from St. Louis to Region of Ontario? While on average our users pay $1,292, our data indicates the cheapest price to be $223. The most popular route (Lambert-St Louis - Toronto Pearson Intl), is priced around $259.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Ontario 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 St. Louis to Region of Ontario?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Region of Ontario (average of $243). Flying from St. Louis to Region of Ontario in July is currently the most expensive (average of $359). 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

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.

Alternative routes for St. Louis to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
St. Louis to Vancouver Intl flights
Kansas City to Vancouver Intl flights
St. Louis to Pearson Intl flights
Kansas City to Calgary flights
St. Louis to Calgary flights
Kansas City to Pearson Intl flights
Kansas City to Pierre Elliott Trudeau Intl flights
St. Louis to Edmonton flights
St. Louis to Pierre Elliott Trudeau Intl flights
Springfield to Vancouver Intl flights
Kansas City to Québec City flights
Kansas City to Halifax flights
Kansas City to Kelowna flights
Springfield to Pearson Intl flights
Kansas City to Winnipeg flights
Kansas City to Victoria flights
St. Louis to Ottawa flights
Kansas City to Toronto Island flights
Joplin to Pearson Intl flights
Springfield to Toronto Island flights
St. Louis to Winnipeg flights
Kansas City to Edmonton flights
St. Louis to Québec City flights
Kansas City to Ottawa flights
St. Louis to Halifax flights
St. Louis to Saskatoon flights
Kansas City to Saskatoon flights
St. Louis to Kelowna flights
St. Louis to Grande Prairie flights
Columbia to Pearson Intl flights
Springfield to Calgary flights
Kansas City to Moncton flights
St. Louis to Sydney flights
Kansas City to St. John's flights
Springfield to Pierre Elliott Trudeau Intl flights
Joplin to Pierre Elliott Trudeau Intl flights
St. Louis to Victoria flights
St. Louis to St. John's flights
Columbia to Pierre Elliott Trudeau Intl flights

Top 3 airlines flying from St. Louis to Ontario

Discover the top 3 airlines that operate flights from St. Louis to Ontario. 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 December 19, 2024.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$202Average$580FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$226Average$562FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$304Average$578FlexibilityNo cancel feeOn-time71%
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.