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

For one-way options, check prices for Air Canada. According to our data, you can fly for as low as C$ 315. Users have also found prices from C$ 325 and C$ 339 on Delta and United Airlines, respectively.

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

While some choose either Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis or Ottawa - Lambert-St Louis, Toronto Pearson Intl - Lambert-St Louis is the most popular route from Region of Ontario to St. Louis.

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

Looking for the cheapest flight from Region of Ontario to St. Louis? While on average our users pay C$ 680, our data indicates the cheapest price to be C$ 502. The most popular route (Toronto Pearson Intl - Lambert-St Louis), is priced around C$ 419.

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

Consider Air Canada (79%), Jazz (79%) or United Airlines (79%) when booking your flight. These represent the most reliable airlines when flying from Region of Ontario to St. Louis.

What are the most popular airlines that fly from Region of Ontario to St. Louis?

Before booking your flight from Region of Ontario to St. Louis check out the most popular airlines for this route: Air Canada, United Airlines or WestJet.

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

Find a great deal and save up to 224% by booking at least 47 days prior to your desired departure date, rather than waiting until the week of travel. According to our data, there are a number of flights available from Region of Ontario to St. Louis within the next two weeks, with the cheapest ticket starting at C$ 707.

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

Flights from Region of Ontario to St. Louis lean towards being more expensive in January. Prices are generally better when you fly from Region of Ontario to St. Louis in May, with the cheapest ticket starting at C$ 398.

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

Most people fly into Lambert-St Louis (STL) if they book a flight to St. Louis from Ontario. Lambert-St Louis is conveniently located just 20.4 km from St. Louis’s city centre.

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

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

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

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

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

Yes. Cheapflights offers flight deals from Ontario to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

C$ 216+ Flights from Ontario to St. Louis

Cheap flight deals from Ontario to St. Louis

Round-trip from	C$ 542
One-way from	C$ 230
Popular in	January
Cheapest in	May
Average price	C$ 754
Good round-trip deal	C$ 543 or less
Good one-way deal	C$ 643 or less

Air Canada
1/5-7/5
Nonstop
4h 13m total
Ontario to St. Louis

Search Deals

8/5
1 total stop
9h 06m total
Ontario to St. Louis

Search Deals

Highest demand for flights based on searches. 4% potential increase in price (C$ 47 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 1% potential price decrease (C$ 11 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in March 2025

Search Deals

Price to beat on a round-trip flight from Ontario to Lambert-St Louis.

Search Deals

Price to beat on a one-way flight from Ontario to Lambert-St Louis.

Search Deals

Find flight deals from Ontario to St. Louis

Cheapest flights from Ontario to St. Louis
Explore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 31 March 2025.

Thu 1/56:30 p.m.YYZ - STL

Nonstop2h 13mAir Canada

Wed 7/52:30 p.m.STL - YYZ

Nonstop2h 00mAir Canada

Deal found 30/3C$ 542

Thu 10/47:25 p.m.YYZ - STL

1 stop23h 18mMultiple Airlines

Sun 13/44:57 p.m.STL - YYZ

1 stop19h 58mMultiple Airlines

Deal found 31/3C$ 551

Wed 30/410:20 a.m.YYZ - STL

1 stop5h 26mWestJet

Wed 7/512:30 p.m.STL - YYZ

1 stop7h 14mWestJet

Deal found 30/3C$ 558

Thu 15/511:30 a.m.YYZ - STL

Nonstop2h 06mUnited Airlines

Thu 22/55:00 a.m.STL - YYZ

1 stop8h 38mUnited Airlines

Deal found 30/3C$ 608

Fri 25/49:45 a.m.YYZ - STL

1 stop4h 16mDelta

Sun 18/56:00 a.m.STL - YYZ

1 stop4h 40mDelta

Deal found 29/3C$ 615

Thu 1/56:45 a.m.YUL - STL

1 stop11h 30mMultiple Airlines

Thu 8/59:50 a.m.STL - YUL

3 stops13h 47mMultiple Airlines

Deal found 31/3C$ 624

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mAir Canada

Thu 8/51:30 p.m.STL - YUL

Nonstop2h 30mAir Canada

Deal found 31/3C$ 640

Thu 1/57:10 a.m.YUL - STL

1 stop6h 51mDelta

Thu 8/56:45 a.m.STL - YUL

1 stop4h 15mDelta

Deal found 31/3C$ 654

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mUnited Airlines

Sun 4/51:30 p.m.STL - YUL

Nonstop2h 30mUnited Airlines

Deal found 31/3C$ 656

Thu 17/49:50 a.m.YOW - STL

3 stops33h 51mMultiple Airlines

Tue 22/46:10 p.m.STL - YOW

2 stops20h 00mMultiple Airlines

Deal found 29/3C$ 700

Thu 15/56:15 a.m.YUL - STL

1 stop18h 11mWestJet

Mon 19/56:05 p.m.STL - YUL

2 stops29h 32mWestJet

Deal found 30/3C$ 786

Thu 8/510:37 a.m.YOW - STL

1 stop7h 46mUnited Airlines

Sat 10/57:24 a.m.STL - YOW

1 stop8h 19mUnited Airlines

Deal found 30/3C$ 874

Best flights from Ontario to St. Louis
Discover carefully curated flight deals from Ontario to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated 31 March 2025.

Thu 1/56:30 p.m.YYZ - STL

Nonstop2h 13mAir Canada

Wed 7/52:30 p.m.STL - YYZ

Nonstop2h 00mAir Canada

Deal found 30/3C$ 542

Wed 30/410:20 a.m.YYZ - STL

1 stop5h 26mWestJet

Wed 7/512:30 p.m.STL - YYZ

1 stop7h 14mWestJet

Deal found 30/3C$ 558

Sat 12/47:15 a.m.YYZ - STL

1 stop17h 31mMultiple Airlines

Sun 13/44:57 p.m.STL - YYZ

1 stop19h 58mMultiple Airlines

Deal found 30/3C$ 593

Thu 15/511:30 a.m.YYZ - STL

Nonstop2h 06mUnited Airlines

Thu 22/55:00 a.m.STL - YYZ

1 stop8h 38mUnited Airlines

Deal found 30/3C$ 608

Fri 25/49:45 a.m.YYZ - STL

1 stop4h 16mDelta

Sun 18/56:00 a.m.STL - YYZ

1 stop4h 40mDelta

Deal found 29/3C$ 615

Thu 10/47:47 a.m.YUL - STL

2 stops7h 58mAmerican Airlines

Sun 13/45:45 a.m.STL - YUL

2 stops10h 00mAmerican Airlines

Deal found 29/3C$ 983

Fri 9/54:45 p.m.YYZ - STL

2 stops30h 07mAlaska Airlines

Tue 13/56:52 a.m.STL - YYZ

2 stops31h 08mAlaska Airlines

Deal found 30/3C$ 1,062

Thu 1/56:45 a.m.YUL - STL

1 stop11h 30mMultiple Airlines

Thu 8/59:50 a.m.STL - YUL

3 stops13h 47mMultiple Airlines

Deal found 31/3C$ 624

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mAir Canada

Thu 8/51:30 p.m.STL - YUL

Nonstop2h 30mAir Canada

Deal found 31/3C$ 640

Thu 1/57:10 a.m.YUL - STL

1 stop6h 51mDelta

Thu 8/56:45 a.m.STL - YUL

1 stop4h 15mDelta

Deal found 31/3C$ 654

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mUnited Airlines

Sun 4/51:30 p.m.STL - YUL

Nonstop2h 30mUnited Airlines

Deal found 31/3C$ 656

Thu 17/49:50 a.m.YOW - STL

3 stops33h 51mMultiple Airlines

Tue 22/46:10 p.m.STL - YOW

2 stops20h 00mMultiple Airlines

Deal found 29/3C$ 700

Direct flights from Ontario to St. Louis
Explore direct flight options from Ontario to St. Louis based on user searches, and compare prices and availability for your desired travel dates. Data last updated 31 March 2025.

Thu 1/56:30 p.m.YYZ - STL

Nonstop2h 13mAir Canada

Wed 7/52:30 p.m.STL - YYZ

Nonstop2h 00mAir Canada

Deal found 30/3C$ 542

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mAir Canada

Thu 8/51:30 p.m.STL - YUL

Nonstop2h 30mAir Canada

Deal found 31/3C$ 640

Thu 1/56:10 p.m.YUL - STL

Nonstop2h 48mUnited Airlines

Sun 4/51:30 p.m.STL - YUL

Nonstop2h 30mUnited Airlines

Deal found 31/3C$ 656

Wed 23/41:40 p.m.YYZ - STL

Nonstop2h 09mUnited Airlines

Wed 30/43:30 p.m.STL - YYZ

Nonstop2h 00mUnited Airlines

Deal found 30/3C$ 717

Thu 10/41:40 p.m.YYZ - STL

Nonstop2h 09mMultiple Airlines

Fri 11/43:30 p.m.STL - YYZ

Nonstop2h 00mMultiple Airlines

Deal found 30/3C$ 1,453

Last-minute flights from Ontario to St. Louis
Discover last-minute flight deals from Ontario to St. Louis. Data last updated 31 March 2025 and is based on user searches.

Fri 4/45:15 p.m.YYZ - STL

1 stop7h 31mMultiple Airlines

Mon 7/44:57 p.m.STL - YYZ

1 stop24h 13mMultiple Airlines

Deal found 29/3C$ 552

Thu 10/47:25 p.m.YYZ - STL

1 stop23h 18mMultiple Airlines

Sun 13/44:57 p.m.STL - YYZ

1 stop19h 58mMultiple Airlines

Deal found 31/3C$ 551

Thu 10/46:45 a.m.YUL - STL

1 stop18h 01mMultiple Airlines

Sun 13/46:10 p.m.STL - YUL

1 stop19h 45mMultiple Airlines

Deal found 29/3C$ 697

Thu 10/46:49 p.m.YYZ - STL

1 stop3h 47mWestJet

Tue 15/46:00 a.m.STL - YYZ

1 stop5h 13mWestJet

Deal found 30/3C$ 802

Thu 10/41:40 p.m.YYZ - STL

Nonstop2h 09mAir Canada

Tue 15/46:30 a.m.STL - YYZ

1 stop4h 45mAir Canada

Deal found 30/3C$ 869

Thu 10/41:40 p.m.YYZ - STL

Nonstop2h 09mUnited Airlines

Sun 13/48:00 a.m.STL - YYZ

1 stop9h 45mUnited Airlines

Deal found 31/3C$ 910

Thu 10/47:47 a.m.YUL - STL

2 stops7h 58mAmerican Airlines

Sun 13/45:45 a.m.STL - YUL

2 stops10h 00mAmerican Airlines

Deal found 29/3C$ 983

Thu 10/44:45 p.m.YYZ - STL

2 stops30h 27mAlaska Airlines

Tue 15/46:44 a.m.STL - YYZ

1 stop31h 16mAlaska Airlines

Deal found 30/3C$ 2,050

Thu 17/49:50 a.m.YOW - STL

3 stops33h 51mMultiple Airlines

Tue 22/46:10 p.m.STL - YOW

2 stops20h 00mMultiple Airlines

Deal found 29/3C$ 700

Mon 21/46:00 p.m.YUL - STL

1 stop6h 36mDelta

Sat 26/41:46 p.m.STL - YUL

1 stop8h 42mDelta

Deal found 30/3C$ 696

Mon 21/46:45 a.m.YUL - STL

2 stops11h 02mWestJet

Sat 26/46:00 a.m.STL - YUL

1 stop6h 56mWestJet

Deal found 30/3C$ 840

Wed 23/47:20 a.m.YYZ - STL

2 stops8h 22mUnited Airlines

Fri 25/41:43 p.m.STL - YYZ

1 stop8h 08mUnited Airlines

Deal found 30/3C$ 658

One-way flights from Ontario to St. Louis
Search for one-way flight options from Ontario to St. Louis. Find affordable one-way fares based on user searches. Data last updated 31 March 2025.

Thu 8/54:00 p.m.YYZ - STL

1 stop9h 06mMultiple Airlines

Deal found 30/3C$ 230

Sun 13/49:25 a.m.YOW - STL

1 stop15h 21mMultiple Airlines

Deal found 30/3C$ 312

Sun 4/53:00 p.m.YYZ - STL

1 stop5h 58mAir Canada

Deal found 30/3C$ 315

Sat 10/57:45 a.m.YYZ - STL

1 stop5h 09mDelta

Deal found 30/3C$ 325

Sat 10/56:30 p.m.YYZ - STL

Nonstop2h 13mUnited Airlines

Deal found 30/3C$ 339

Sat 7/66:10 p.m.YUL - STL

Nonstop2h 48mAir Canada

Deal found 29/3C$ 365

Sat 31/512:00 p.m.YYZ - STL

2 stops12h 26mWestJet

Deal found 29/3C$ 365

Tue 1/76:45 a.m.YUL - STL

1 stop18h 04mMultiple Airlines

Deal found 31/3C$ 371

Sat 7/62:00 p.m.YUL - STL

2 stops9h 45mUnited Airlines

Deal found 29/3C$ 374

Thu 3/76:10 a.m.YUL - STL

1 stop18h 10mWestJet

Deal found 31/3C$ 437

Fri 19/912:45 p.m.YUL - STL

1 stop8h 50mDelta

Deal found 30/3C$ 469

Thu 29/52:35 p.m.YOW - STL

1 stop6h 23mAir Canada

Deal found 30/3C$ 475

Cheapflights Fare Finder

Use the filters below to find and compare flights from Ontario to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 1/5

6:30 p.m.-7:43 p.m.

Nonstop2h 13m

Lambert-St Louis

Wed 7/5

2:30 p.m.-5:30 p.m.

Nonstop2h 00m

C$ 542

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 10/4

7:25 p.m.-5:43 p.m.

1 stop23h 18m

Lambert-St Louis

Sun 13/4

4:57 p.m.-1:55 p.m.

1 stop19h 58m

C$ 551

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Wed 30/4

10:20 a.m.-2:46 p.m.

1 stop5h 26m

Lambert-St Louis

Wed 7/5

12:30 p.m.-8:44 p.m.

1 stop7h 14m

C$ 558

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Thu 15/5

11:30 a.m.-12:36 p.m.

Nonstop2h 06m

Lambert-St Louis

Thu 22/5

5:00 a.m.-2:38 p.m.

1 stop8h 38m

C$ 608

TorontoSt. Louis

YYZ - STL

YYZSTL

Toronto Pearson Intl

Fri 25/4

9:45 a.m.-1:01 p.m.

1 stop4h 16m

Lambert-St Louis

Sun 18/5

6:00 a.m.-11:40 a.m.

1 stop4h 40m

C$ 615

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 1/5

6:45 a.m.-5:15 p.m.

1 stop11h 30m

Lambert-St Louis

Thu 8/5

9:50 a.m.-12:37 a.m.

3 stops13h 47m

C$ 624

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 1/5

6:10 p.m.-7:58 p.m.

Nonstop2h 48m

Lambert-St Louis

Thu 8/5

1:30 p.m.-5:00 p.m.

Nonstop2h 30m

C$ 640

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 1/5

7:10 a.m.-1:01 p.m.

1 stop6h 51m

Lambert-St Louis

Thu 8/5

6:45 a.m.-12:00 p.m.

1 stop4h 15m

C$ 654

MontrealSt. Louis

YUL - STL

YULSTL

Montreal Pierre Elliott Trudeau Intl

Thu 1/5

6:10 p.m.-7:58 p.m.

Nonstop2h 48m

Lambert-St Louis

Thu 8/5

8:25 a.m.-5:15 p.m.

1 stop7h 50m

C$ 656

OttawaSt. Louis

YOW - STL

YOWSTL

Ottawa

Thu 17/4

9:50 a.m.-6:41 p.m.

3 stops33h 51m

Lambert-St Louis

Tue 22/4

6:10 p.m.-3:10 p.m.

2 stops20h 00m

C$ 700

Flights are sorted by cheapest round-trip flights first.

Deals found on 31/3

Showing 1-10 of 31 results

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

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

Cheapflights Insights

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

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

Currently, January is the cheapest month in which you can book a flight from Region of Ontario to St. Louis (average of C$ 365). Flying from Region of Ontario to St. Louis in September is currently the most expensive (average of C$ 491). 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 ON to STL?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Region of Ontario to St. Louis as you normally would.

Rainfall in St. Louis by month

In terms of precipitation, rainfall in St. Louis ranges from 56.0 - 119.0 mm per month. May is typically the wettest month, when rainfall can reach 119.0 mm. February is typically the driest time to visit St. Louis when rainfall is around 56.0 mm.

Temperature in St. Louis by month

If weather is an important factor for your trip to St. Louis, 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 27.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 0.0 C).

Reviews of airlines servicing St. Louis

See what other customers who have flown with Alaska Airlines, Delta and United Airlines from Ontario to St. Louis have to say. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Alaska Airlines

8.0

Very good

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

9,818 reviews

Alaska Airlines

8.0

Very good

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

7,899 reviews

Alaska Airlines

8.0

Very good

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

8,614 reviews

Alaska Airlines

8.0

Very good

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

2,789 reviews

Alaska Airlines

8.0

Very good

9,818 reviews

Check prices

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

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

What airport do you fly into for flights to St. Louis from Ontario?
Most people fly into Lambert-St Louis (STL) if they book a flight to St. Louis from Ontario. Lambert-St Louis is conveniently located just 20.4 km from St. Louis’s city centre.
What are the cheapest airlines to fly from Region of Ontario to St. Louis one-way?
For one-way options, check prices for Air Canada. According to our data, you can fly for as low as C$ 315. Users have also found prices from C$ 325 and C$ 339 on Delta and United Airlines, respectively.
What are the most popular routes from Region of Ontario to St. Louis?
While some choose either Montreal Pierre Elliott Trudeau Intl - Lambert-St Louis or Ottawa - Lambert-St Louis, Toronto Pearson Intl - Lambert-St Louis is the most popular route from Region of Ontario to St. Louis.
What are the most reliable airlines from Region of Ontario to St. Louis?
Consider Air Canada (79%), Jazz (79%) or United Airlines (79%) when booking your flight. These represent the most reliable airlines when flying from Region of Ontario to St. Louis.
What are the cheapest flights from Region of Ontario to St. Louis?
Looking for the cheapest flight from Region of Ontario to St. Louis? While on average our users pay C$ 680, our data indicates the cheapest price to be C$ 502. The most popular route (Toronto Pearson Intl - Lambert-St Louis), is priced around C$ 419.
Can I find deals for flights from Ontario to St. Louis that include hotel bookings?
Yes. In addition to deals on Ontario to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Ontario to St. Louis?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to St. Louis.
Can I find deals for business class flights from Ontario to St. Louis?
Yes. Cheapflights offers flight deals from Ontario to St. Louis 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 Region of Ontario to St. Louis?
Currently, January is the cheapest month in which you can book a flight from Region of Ontario to St. Louis (average of C$ 365). Flying from Region of Ontario to St. Louis in September is currently the most expensive (average of C$ 491). 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

St. Peters

Chesterfield

Browse thousands of different options on Cheapflights for your next trip

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Complete your trip

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Top 3 airlines flying from Ontario to St. Louis

Airline	Cheapest	Average	Flexibility	On-time
Air Canada	CheapestC$ 529	AverageC$ 814	FlexibilityNo cancel fee	On-time67%	Search Air Canada flights
United Airlines	CheapestC$ 599	AverageC$ 706	FlexibilityNo cancel fee	On-time69%	Search United Airlines flights
WestJet	CheapestC$ 631	AverageC$ 781	FlexibilityNo cancel fee	On-time60%	Search WestJet flights

Fly with Cheapflights

How does Cheapflights help users find flights from Ontario to St. Louis?

When you search for this flight from Ontario to St. Louis, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Ontario to St. Louis?

Cheapflights helps you find that perfect flight to St. Louis from Ontario by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Ontario to St. Louis with no change fees?

Certainly. Search results for flights to St. Louis from Ontario shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from Ontario to St. Louis become cheaper?

Yes! Start tracking prices for Ontario to St. Louis flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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Cheap flights from Ontario to St. Louis from C$ 216

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 29/4. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Ontario to St. Louis

Keep the following information in mind while searching for Ontario to St. Louis flight deals. Data was last updated 31 March 2025.

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Find flight deals from Ontario to St. Louis

Cheapest flights from Ontario to St. LouisExplore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 31 March 2025.

Explore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 31 March 2025.

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

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Ontario with our price prediction graph.

Cheapflights Insights

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

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

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

Find hourly flight availability from Ontario to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 31 March 2025.

Rainfall in St. Louis by month

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

Temperature in St. Louis by month

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

Reviews of airlines servicing St. Louis

See what other customers who have flown with Alaska Airlines, Delta and United Airlines from Ontario to St. Louis have to say. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Ontario to St. Louis. 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 into for flights to St. Louis from Ontario?

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

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

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

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

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

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

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

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

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Alternative routes for Ontario to St. Louis

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Top 3 airlines flying from Ontario to St. Louis

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Cheapest flights from Ontario to St. Louis
Explore the most affordable flight options available from Ontario to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 31 March 2025.