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$89+ 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 2/11. Fares are subject to change and may not be available on all flights or dates of travel.
STL — YYZ
Jan 22 — Jan 291
Wed 1/22
Wed 1/29
1 adult, Economy
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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 January 17, 2025.

Round-trip from

$330
(Kiwi.com)

One-way from

$89
(Kiwi.com)
From Lambert-St Louis to Ontario
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One-way flight from Lambert-St Louis to Ontario
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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 January 17, 2025.

This Kiwi.com deal was found by Cheapflights users on 1/16. 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 1/285:05 pmSTL - YYZ
1 stop17h 40mMultiple Airlines
Thu 2/207:05 amYYZ - STL
1 stop8h 37mMultiple Airlines
Deal found 1/16$330
This Kiwi.com deal was found by Cheapflights users on 1/16. 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.
Fri 2/78:31 pmSTL - YUL
2 stops17h 09mMultiple Airlines
Tue 2/116:30 amYUL - STL
1 stop9h 13mMultiple Airlines
Deal found 1/16$416
This WestJet deal was found by Cheapflights users on 1/16. 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 WestJet is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/2411:19 amSTL - YYZ
2 stops24h 18mWestJet
Wed 3/2610:05 amYYZ - STL
1 stop5h 44mWestJet
Deal found 1/16$497
This Delta deal was found by Cheapflights users on 1/16. 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.
Sat 2/151:35 pmSTL - YUL
1 stop19h 51mDelta
Tue 2/186:00 amYUL - STL
1 stop16h 02mDelta
Deal found 1/16$507
This Delta deal was found by Cheapflights users on 1/16. 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.
Thu 2/271:35 pmSTL - YYZ
1 stop9h 04mDelta
Sat 3/110:05 amYYZ - STL
1 stop8h 52mDelta
Deal found 1/16$515
This Kiwi.com deal was found by Cheapflights users on 1/16. 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.
Mon 1/205:05 pmSTL - YOW
2 stops21h 05mMultiple Airlines
Thu 1/234:20 pmYOW - STL
1 stop8h 11mMultiple Airlines
Deal found 1/16$529
This Alaska Airlines deal was found by Cheapflights users on 1/16. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/193:11 pmSTL - YYZ
1 stop22h 44mAlaska Airlines
Mon 3/244:20 pmYYZ - STL
1 stop22h 55mAlaska Airlines
Deal found 1/16$547
This American Airlines deal was found by Cheapflights users on 1/16. 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.
Tue 2/47:20 amSTL - YYZ
1 stop13h 12mAmerican Airlines
Tue 2/1110:59 amYYZ - STL
1 stop12h 09mAmerican Airlines
Deal found 1/16$559
This Justfly.com deal was found by Cheapflights users on 1/16. 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.
Fri 2/1411:50 amSTL - YUL
1 stop10h 32mWestJet
Sun 2/167:00 amYUL - STL
1 stop5h 46mWestJet
Deal found 1/16$604
This American Airlines deal was found by Cheapflights users on 1/15. 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 2/127:18 amSTL - YUL
2 stops8h 32mAmerican Airlines
Sat 2/157:14 amYUL - STL
1 stop17h 42mAmerican Airlines
Deal found 1/15$616
This United Airlines deal was found by Cheapflights users on 1/16. 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.
Tue 4/88:25 amSTL - YYZ
1 stop14h 29mUnited Airlines
Tue 4/151:20 pmYYZ - STL
2 stops27h 27mUnited Airlines
Deal found 1/16$639
This Air Canada deal was found by Cheapflights users on 1/15. 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.
Wed 3/1211:05 amSTL - YYZ
1 stop6h 36mAir Canada
Sun 3/161:50 pmYYZ - STL
Nonstop2h 16mAir Canada
Deal found 1/15$650

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 January 17, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 1/28

5:05 pm-11:45 am

1 stop17h 40m

Toronto Pearson Intl

Thu 2/20

7:05 am-2:42 pm

1 stop8h 37m

$330

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Fri 2/7

8:31 pm-2:40 pm

2 stops17h 09m

Montreal Pierre Elliott Trudeau Intl

Tue 2/11

6:30 am-2:43 pm

1 stop9h 13m

$416

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Mon 3/24

11:19 am-12:37 pm

2 stops24h 18m

Toronto Pearson Intl

Wed 3/26

10:05 am-2:49 pm

1 stop5h 44m

$497

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Sat 2/15

1:35 pm-10:26 am

1 stop19h 51m

Montreal Pierre Elliott Trudeau Intl

Tue 2/18

6:00 am-9:02 pm

1 stop16h 02m

$507

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Thu 2/27

1:35 pm-11:39 pm

1 stop9h 04m

Toronto Pearson Intl

Sat 3/1

10:05 am-5:57 pm

1 stop8h 52m

$515

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Wed 3/19

3:11 pm-2:55 pm

1 stop22h 44m

Toronto Pearson Intl

Mon 3/24

4:20 pm-2:15 pm

1 stop22h 55m

$547

St. LouisToronto

STL - YYZ

STLYYZ

Lambert-St Louis

Tue 2/4

7:20 am-9:32 pm

1 stop13h 12m

Toronto Pearson Intl

Tue 2/11

10:59 am-10:08 pm

1 stop12h 09m

$559

St. LouisOttawa

STL - YOW

STLYOW

Lambert-St Louis

Thu 2/6

4:28 pm-5:15 pm

2 stops23h 47m

Ottawa

Wed 2/12

4:20 pm-2:42 pm

2 stops23h 22m

$563

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Fri 2/14

5:50 pm-11:22 pm

1 stop4h 32m

Montreal Pierre Elliott Trudeau Intl

Mon 2/17

6:00 am-10:17 pm

1 stop17h 17m

$604

St. LouisMontreal

STL - YUL

STLYUL

Lambert-St Louis

Wed 2/12

7:18 am-4:50 pm

2 stops8h 32m

Montreal Pierre Elliott Trudeau Intl

Sat 2/15

7:14 am-11:56 pm

1 stop17h 42m

$616

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/15

Showing 1-10 of 24 results
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2
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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 January 17, 2025.

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.

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 January 17, 2025.
Peruse reviews from past customers who have flown with WestJet, American Airlines and United Airlines 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
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Alaska Airlines
8.0
Very good
9,681 reviews
Alaska Airlines
8.0
Very good
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Delta
8.0
Very good
8,511 reviews
Alaska Airlines
8.0
Very good
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

United Airlines
7.4
Good
8,965 reviews
Alaska Airlines
8.0
Very good
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

WestJet
7.2
Good
2,824 reviews
Alaska Airlines
8.0
Very good
9,681 reviews

Food

7.1

Crew

8.5

Comfort

7.9

Entertainment

7.1

Boarding

8.2

Overall

8.0

Reviews

1 / 10

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

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 $216 on American Airlines. Other airlines that offer cheap prices include United Airlines from $273 and Air Canada from $336 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 (74%), Jazz (74%) or United Airlines (74%) 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 $1,358, our data indicates the cheapest price to be $162. The most popular route (Lambert-St Louis - Toronto Pearson Intl), is priced around $351.

  • 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.

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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
St. Louis to Calgary flights
Kansas City to Vancouver Intl flights
Kansas City to Calgary flights
St. Louis to Pearson Intl flights
Kansas City to Pearson Intl flights
St. Louis to Pierre Elliott Trudeau Intl flights
Kansas City to Pierre Elliott Trudeau Intl flights
St. Louis to Halifax flights
St. Louis to Québec City flights
Springfield to Vancouver Intl flights
Kansas City to Halifax flights
Kansas City to Victoria flights
Kansas City to Winnipeg flights
Kansas City to Kelowna flights
St. Louis to Ottawa flights
St. Louis to Edmonton flights
Kansas City to Québec City flights
Springfield to Pierre Elliott Trudeau Intl flights
St. Louis to St. John's flights
Springfield to Pearson Intl flights
Kansas City to Toronto Island flights
Kansas City to Saskatoon flights
Kansas City to Ottawa flights
St. Louis to Winnipeg flights
Joplin to Pearson Intl flights
St. Louis to Saskatoon flights
Kansas City to St. John's flights
Kansas City to Edmonton flights
St. Louis to Grande Prairie flights
St. Louis to Victoria flights
St. Louis to Sydney flights
Kansas City to Moncton flights
Springfield to Toronto Island flights
St. Louis to Kelowna flights
Springfield to Calgary flights
Columbia to Pierre Elliott Trudeau Intl flights
Joplin to Pierre Elliott Trudeau Intl flights
Columbia to Pearson 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 January 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
Air CanadaCheapest$200Average$605FlexibilityNo cancel feeOn-time67%
United AirlinesCheapest$226Average$557FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$304Average$553FlexibilityNo cancel feeOn-time71%
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