How many flights depart from St. Louis to Region of Ontario on average per week?

As of September 2026, there are 48 flights per week flying from St. Louis to Region of Ontario. The most common day of the week flights depart is Mon, with 15% of flights taking off on this day.

How many flights depart from St. Louis to Region of Ontario on average per day?

6 flights are operational daily from St. Louis to Region of Ontario as of September 2026. The most popular departure time for this route is 2:00PM, with 61% of flights per day taking off in the afternoon.

What is the cheapest airline that flies from Lambert-St Louis to Ontario?

Delta, American Airlines, and Air Canada are the most popular carriers operating from Lambert-St Louis to Ontario

What airlines fly to Region of Ontario?

Air Canada, United Airlines and American Airlines are the top three most popular airlines that fly to Region of Ontario from St. Louis according to our data. Air Canada is the first choice among our users, with 70% of people opting to fly with this airline when traveling to Region of Ontario. Keep in mind that there are 3 different airlines that fly to Region of Ontario on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Lambert-St Louis Airport to Ontario?

Prices for flights from Lambert-St Louis Airport to Ontario were last updated today.

How many operators does momondo search for flights from Lambert-St Louis Airport to Ontario?

The number of operators available for flights from Lambert-St Louis Airport to Ontario is 3 as of September 2026.

How old do you have to be to fly from Lambert-St Louis Airport to Ontario?

The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Ontario.

What documentation or ID do you need to fly to Ontario?

The required travel and health documents for your Ontario trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ontario. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$128 Cheap Flights from St. Louis to Ontario in 2026

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to Ontario

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

4:26 pm - 2:10 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

20h 44m1 stop Orlando

12:20 pm - 5:40 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

30h 20m2 stops Tampa Atlanta Hartsfield-Jackson

$353Multiple Airlines

Mon, Nov 9 - Tue, Nov 17

6:05 pm - 2:10 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

19h 05m1 stop Orlando

5:15 pm - 12:41 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

8h 26m1 stop Orlando

$354Multiple Airlines

Mon, Dec 7 - Fri, Dec 11

5:00 am - 2:33 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 33m1 stop Chicago O'Hare Intl

11:40 am - 8:57 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 17m1 stop Chicago O'Hare Intl

$355American Airlines

Thu, Oct 8 - Thu, Oct 15

5:00 am - 2:32 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 32m1 stop Chicago O'Hare Intl

7:29 am - 4:53 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 24m1 stop Chicago O'Hare Intl

$355American Airlines

Thu, Oct 1 - Tue, Oct 6

7:29 am - 5:44 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

9h 15m1 stop Chicago O'Hare Intl

7:29 am - 4:53 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 24m1 stop Chicago O'Hare Intl

$355American Airlines

Thu, Oct 8 - Thu, Oct 15

6:05 pm - 1:40 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

18h 35m1 stop Orlando

7:15 am - 12:41 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

18h 26m1 stop Orlando

$372Multiple Airlines

Fri, Dec 4 - Mon, Dec 7

8:00 am - 6:31 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

9h 31m1 stop Chicago O'Hare Intl

2:00 pm - 9:21 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

8h 21m1 stop Chicago O'Hare Intl

$543United Airlines

Mon, Oct 19 - Tue, Oct 20

1:29 pm - 11:26 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 57m1 stop Chicago O'Hare Intl

1:00 pm - 7:41 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

7h 41m1 stop Chicago O'Hare Intl

$543United Airlines

Wed, Oct 7 - Sat, Oct 17

8:55 am - 3:10 pmSTL Lambert-St Louis-YOW Ottawa

5h 15m1 stop Toronto Pearson Intl

2:50 pm - 6:41 pmYOW Ottawa-STL Lambert-St Louis

4h 51m1 stop Montreal Pierre Elliott Trudeau Intl

$556Air Canada

Thu, Oct 1 - Tue, Oct 6

4:05 pm - 6:59 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

2:10 pm - 3:26 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 16mnonstop

$557Air Canada

Sun, Nov 1 - Tue, Nov 3

Cheap last minute flights

Enter your travel dates to find the best prices.

8:55 am - 11:49 amSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

7:15 pm - 8:20 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mnonstop

$635Air Canada

Wed, Sep 16 - Wed, Sep 23

2:40 pm - 5:34 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

2:00 pm - 6:41 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

5h 41m1 stop Montreal Pierre Elliott Trudeau Intl

$638Air Canada

Wed, Sep 16 - Wed, Sep 23

12:10 pm - 7:53 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

6h 43m1 stop Montreal Pierre Elliott Trudeau Intl

2:00 pm - 6:41 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

5h 41m1 stop Montreal Pierre Elliott Trudeau Intl

$642Air Canada

Wed, Sep 16 - Wed, Sep 23

5:19 pm - 4:40 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

22h 21m1 stop Orlando

7:25 am - 5:54 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

11h 29m2 stops Boston Logan Intl Orlando

$718Multiple Airlines

Thu, Sep 17 - Thu, Sep 24

2:00 pm - 9:55 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

30h 55m2 stops Jonesboro Nashville Intl

6:00 am - 9:29 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

4h 29m1 stop Detroit Metropolitan Wayne County

$744Multiple Airlines

Wed, Sep 16 - Wed, Sep 23

2:29 pm - 2:05 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

22h 36m2 stops Atlanta Hartsfield-Jackson Fort Lauderdale

8:35 pm - 11:27 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

15h 52m1 stop Las Vegas Harry Reid Intl

$759Multiple Airlines

Wed, Sep 16 - Thu, Sep 17

6:00 am - 2:40 pmSTL Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl

7h 40m2 stops Chicago O'Hare Intl Washington, D.C. Dulles Intl

6:00 am - 3:43 pmYUL Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis

10h 43m2 stops Newark Chicago O'Hare Intl

$841United Airlines

Thu, Sep 17 - Thu, Sep 24

5:30 pm - 11:59 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

5h 29m1 stop Chicago O'Hare Intl

8:00 pm - 11:17 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

16h 17m1 stop Newark

$868United Airlines

Wed, Sep 16 - Mon, Sep 21

5:00 am - 2:32 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

8h 32m1 stop Chicago O'Hare Intl

11:40 am - 8:44 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

10h 04m1 stop Chicago O'Hare Intl

$944American Airlines

Wed, Sep 16 - Mon, Sep 21

9:58 am - 6:45 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

7h 47m1 stop New York LaGuardia

6:15 am - 10:29 amYYZ Toronto Pearson Intl-STL Lambert-St Louis

5h 14m1 stop Philadelphia

$980American Airlines

Wed, Sep 16 - Mon, Sep 21

Cheap direct flights

Enter your travel dates to find the best prices.

2:40 pm - 5:34 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

7:15 pm - 8:20 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mnonstop

$557Air Canada

Mon, Oct 5 - Wed, Oct 7

4:05 pm - 6:59 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

2:10 pm - 3:23 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mnonstop

$557Air Canada

Fri, Oct 30 - Mon, Nov 2

2:40 pm - 5:34 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

7:15 pm - 8:20 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 05mnonstop

$557Air Canada

Thu, Oct 1 - Tue, Oct 6

4:05 pm - 7:05 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mnonstop

2:10 pm - 3:26 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 16mnonstop

$557Air Canada

Mon, Nov 9 - Mon, Nov 16

4:05 pm - 6:59 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

2:10 pm - 3:23 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 13mnonstop

$790United Airlines

Tue, Oct 27 - Thu, Oct 29

4:05 pm - 6:59 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

1h 54mnonstop

2:10 pm - 3:26 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 16mnonstop

$805United Airlines

Sun, Nov 1 - Tue, Nov 3

4:05 pm - 7:05 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mnonstop

2:10 pm - 3:26 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 16mnonstop

$874United Airlines

Thu, Nov 26 - Fri, Nov 27

12:10 pm - 3:41 pmSTL Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl

2h 31mnonstop

4:55 pm - 6:41 pmYUL Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis

2h 46mnonstop

$912United Airlines

Fri, Oct 2 - Tue, Oct 6

4:05 pm - 7:05 pmSTL Lambert-St Louis-YYZ Toronto Pearson Intl

2h 00mnonstop

2:10 pm - 3:26 pmYYZ Toronto Pearson Intl-STL Lambert-St Louis

2h 16mnonstop

$1,111Multiple Airlines

Thu, Nov 19 - Thu, Nov 26

12:10 pm - 3:41 pmSTL Lambert-St Louis-YUL Montreal Pierre Elliott Trudeau Intl

2h 31mnonstop

4:55 pm - 6:41 pmYUL Montreal Pierre Elliott Trudeau Intl-STL Lambert-St Louis

2h 46mnonstop

$2,942Multiple Airlines

Fri, Sep 25 - Mon, Sep 28

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

American Airlines flights from St. Louis to Region of Ontario

Our best American Airlines deals on St. Louis to Region of Ontario flight tickets

American Airlines

Oct 1

STL5:00 amLambert-St Louis

8h 32m

1 stop

YYZ2:32 pmToronto Pearson Intl

Oct 6

YYZ1:15 pmToronto Pearson Intl

12h 04m

1 stop

STL12:19 amLambert-St Louis

$355

American Airlines

Nov 19

STL6:00 amLambert-St Louis

7h 33m

1 stop

YYZ2:33 pmToronto Pearson Intl

Nov 26

YYZ6:00 amToronto Pearson Intl

11h 34m

2 stops

STL4:34 pmLambert-St Louis

$364

American Airlines

Oct 2

STL5:00 amLambert-St Louis

8h 32m

1 stop

YYZ2:32 pmToronto Pearson Intl

Oct 7

YYZ11:40 amToronto Pearson Intl

10h 17m

1 stop

STL8:57 pmLambert-St Louis

$382

WestJet flights from St. Louis to Region of Ontario

Our best WestJet deals on St. Louis to Region of Ontario flight tickets

WestJet

Sep 25

STL5:47 pmLambert-St Louis

4h 26m

1 stop

YYZ11:13 pmToronto Pearson Intl

Sep 26

YYZ6:30 pmToronto Pearson Intl

19h 53m

2 stops

STL1:23 pmLambert-St Louis

$696

WestJet

Sep 25

STL11:21 amLambert-St Louis

18h 44m

2 stops

YUL7:05 amMontreal Pierre Elliott Trudeau Intl

Sep 28

YUL8:00 pmMontreal Pierre Elliott Trudeau Intl

15h 55m

2 stops

STL10:55 amLambert-St Louis

$978

WestJet

Sep 19

STL5:46 pmLambert-St Louis

36h 19m

2 stops

YUL7:05 amMontreal Pierre Elliott Trudeau Intl

Sep 22

YUL8:00 pmMontreal Pierre Elliott Trudeau Intl

28h 16m

2 stops

STL11:16 pmLambert-St Louis

$1,109

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Mon 11/9

4:26 pm-2:10 pm

1 stop20h 44m

Toronto Pearson Intl

Tue 11/17

12:20 pm-5:40 pm

2 stops30h 20m

$353

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Mon 12/7

6:05 pm-2:10 pm

1 stop19h 05m

Toronto Pearson Intl

Fri 12/11

5:15 pm-12:41 am

1 stop8h 26m

$354

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Thu 10/8

5:00 am-2:33 pm

1 stop8h 33m

Toronto Pearson Intl

Thu 10/15

11:40 am-8:57 pm

1 stop10h 17m

$355

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Thu 10/1

5:00 am-2:32 pm

1 stop8h 32m

Toronto Pearson Intl

Tue 10/6

7:29 am-4:53 pm

1 stop10h 24m

$355

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Thu 10/8

7:29 am-5:44 pm

1 stop9h 15m

Toronto Pearson Intl

Thu 10/15

7:29 am-4:53 pm

1 stop10h 24m

$355

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Fri 12/4

6:05 pm-1:40 pm

1 stop18h 35m

Toronto Pearson Intl

Mon 12/7

7:15 am-12:41 am

1 stop18h 26m

$372

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Mon 10/19

8:00 am-6:31 pm

1 stop9h 31m

Toronto Pearson Intl

Tue 10/20

2:00 pm-9:21 pm

1 stop8h 21m

$543

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Wed 10/7

1:29 pm-11:26 pm

1 stop8h 57m

Toronto Pearson Intl

Sat 10/17

1:00 pm-7:41 pm

1 stop7h 41m

$543

St. LouisOttawa

STL Lambert-St Louis - YOW Ottawa

STLYOW

Lambert-St Louis

Thu 10/1

8:55 am-3:10 pm

1 stop5h 15m

Ottawa

Tue 10/6

2:50 pm-6:41 pm

1 stop4h 51m

$556

Quickest round-trip

St. LouisToronto

STL Lambert-St Louis - YYZ Toronto Pearson Intl

STLYYZ

Lambert-St Louis

Sun 11/1

4:05 pm-6:59 pm

Nonstop1h 54m

Toronto Pearson Intl

Tue 11/3

2:10 pm-3:26 pm

Nonstop2h 16m

$557

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from St. Louis to Region of Ontario

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

Other information

What is the cheapest month to fly to Region of Ontario?

The month of March is, on average, the cheapest month to fly to Region of Ontario from St. Louis, with most prices found around $425. If you aren’t able to travel during the month of March, then book flights to Region of Ontario from St. Louis during December instead. Flights to Region of Ontario in December, while not as cheap as those in March, still average around $473.

What is the cheapest day to depart on your flight to Region of Ontario?

According to our data, Tuesday is the cheapest day to fly to Region of Ontario from St. Louis. The lowest ticket price found for a Tuesday departure recently was $786. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. Flights from St. Louis to Region of Ontario on a Saturday will generally be more expensive and average around $968. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

What is the cheapest time of day to depart on your flight to Region of Ontario?

According to our data, the cheapest time of day to fly to Region of Ontario is in the morning. momondo users have found flights departing from St. Louis to Region of Ontario in the morning for as low as $717. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights at noon are often more expensive with an average ticket price of $1,062.

What is the cheapest Lambert-St Louis to Ontario flight route?

Fly from Lambert-St Louis to Toronto Pearson Intl for the best Lambert-St Louis - Ontario flight prices

What cabin class options are available on St. Louis to Region of Ontario flights?

There are 4 cabin classes available to choose from on St. Louis to Region of Ontario flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on St. Louis to Region of Ontario flights?

You could potentially save up to 43% on your flight if you consider stops on a St. Louis to Region of Ontario flight.

Cheap St. Louis to Region of Ontario flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Region of Ontario

Best Price Found	$128
Fastest flight time	1h 54m
Direct flights	Every day
Airports in Region of Ontario	125 airports

The best one-way flight to Region of Ontario from St. Louis in the past 72 hours is $128. The best round-trip flight deal from St. Louis to Region of Ontario found on momondo in the last 72 hours is $353.

The fastest flight from St. Louis to Region of Ontario takes 1h 54m

Direct flights go from St. Louis to Region of Ontario every day.

There are 125 airports in Region of Ontario. From St. Louis there are direct flights to Montreal Pierre Elliott Trudeau Intl (YUL), Toronto Pearson Intl (YYZ).

Search flight deals

Frequently asked questions about flying from St. Louis to Ontario

When did momondo last update prices for flights from Lambert-St Louis Airport to Ontario?
Prices for flights from Lambert-St Louis Airport to Ontario were last updated today.
How many operators does momondo search for flights from Lambert-St Louis Airport to Ontario?
The number of operators available for flights from Lambert-St Louis Airport to Ontario is 3 as of September 2026.
How old do you have to be to fly from Lambert-St Louis Airport to Ontario?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Ontario.
What documentation or ID do you need to fly to Ontario?
The required travel and health documents for your Ontario trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Ontario. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from St. Louis to Region of Ontario?
momondo data reveals that the most frequently booked plane model on the route from St. Louis to Region of Ontario is Canadair (Bombardier) Regional Jet 900, representing 52.35% of all bookings. The subsequent popular models are Embraer 175 at 22.94%, Boeing 787-8 Dreamliner at 5.29%, and Airbus A220-300 at 4.71%.

Best airlines flying from St. Louis to Region of Ontario

Compare and see reviews for airlines that fly from St. Louis to Region of Ontario with momondo

Airline	Rating	Free Cancellation	Price
Air Canada	PriceFrom $139	Free Cancellation	Rating 7.1 11,609 reviews	Search Air Canada flights
United Airlines	PriceFrom $203	Free Cancellation	Rating 7.4 10,196 reviews	Search United Airlines flights
American Airlines	PriceFrom $270	Free Cancellation	Rating 7.1 12,048 reviews	Search American Airlines flights

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Ontario?

It is quick and easy to find St. Louis to Ontario flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Ontario that suits you.

Can I find flights from St. Louis to Ontario with flexible booking policies on momondo?

Yes. All flights to Ontario from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from St. Louis to Ontario?

Once you have performed a search for St. Louis to Ontario flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from St. Louis to Ontario right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Ontario, momondo offers a useful price alert feature which will track prices for flights to Ontario from St. Louis and alert you when they change.

An easier way to manage your Region of Ontario trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Sun 10/11

Sun 10/18

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Ontario

Popular cities

Other flights from St. Louis

Other flights to Ontario

Airlines

Complete your trip

Feeling lucky

Popular cities in Ontario

Flights to Torontofrom $159

Flights to Vancouverfrom $152

Flights to Montrealfrom $237

Flights to Calgaryfrom $187

Flights to Ottawafrom $207

Flights to Halifaxfrom $264

Flights to Winnipegfrom $260

Flights to Québec Cityfrom $331

Flights to Kelownafrom $226

Flights to St. John'sfrom $338

Flights to Saskatoonfrom $252

Flights to Reginafrom $332

Cheap flights from St. Louis to Ontario from $128

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Ontario departing on 10/23. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Find the cheapest flights from St. Louis to Ontario

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

American Airlines flights from St. Louis to Region of Ontario

Our best American Airlines deals on St. Louis to Region of Ontario flight tickets

WestJet flights from St. Louis to Region of Ontario

Our best WestJet deals on St. Louis to Region of Ontario flight tickets

momondo Fare Finder

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

See travel insights to Ontario from

How to get the cheapest flight ticket from St. Louis to Region of Ontario

What is the cheapest month to fly to Region of Ontario?

What is the cheapest day to depart on your flight to Region of Ontario?

What is the cheapest time of day to depart on your flight to Region of Ontario?

What is the cheapest Lambert-St Louis to Ontario flight route?

What cabin class options are available on St. Louis to Region of Ontario flights?

Can stopping save me money on St. Louis to Region of Ontario flights?

What is the cheapest airline that flies from Lambert-St Louis to Ontario?

What airlines fly to Region of Ontario?

How many flights depart from St. Louis to Region of Ontario on average per day?

How many flights depart from St. Louis to Region of Ontario on average per week?

Cheap St. Louis to Region of Ontario flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Airports in Region of Ontario

Frequently asked questions about flying from St. Louis to Ontario

Best airlines flying from St. Louis to Region of Ontario

Compare and see reviews for airlines that fly from St. Louis to Region of Ontario with momondo

Why use momondo?

An easier way to manage your Region of Ontario trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to Ontario

Popular cities in Ontario

Popular flights according to clicks in the last 7 days on momondo

St. Louis flight routes

According to popular flight searches on momondo this year

Region of Ontario flight routes

According to popular flight searches on momondo this year

Fly your favorite airline to Ontario

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Complete your trip to Ontario

Explore popular destinations other users love

According to popular flight searches on momondo this year