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Cheap flights from Ontario to St. Louis from $60

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to St. Louis departing on 1/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Ontario to St. Louis

Cheap round-trip flights

These are some of the best round-trip flight deals from Ontario to St. Louis that have been recently found on momondo from popular airlines, departing in the coming months.

Cheap one-way flights

Flying one-way? These are some of the best deals recently discovered on momondo for flights from Ontario to St. Louis.

Cheap last minute flights

Planning a quick getaway from Ontario to St. Louis? These are the last-minute flight deals available now.

Cheap direct flights

If you prefer a non-stop journey, check out our latest direct flight deals to St. Louis, so you can enjoy a seamless trip without layovers.

Cheap bus & train deals from Ontario to St. Louis

Find recent round-trip train or bus tickets from Ontario to St. Louis.

All round-trip flight deals to St. Louis

The cheapest plane tickets to St. Louis found on KAYAK recently.
8:04 am - 7:34 pmONT-STL
9h 30m1 stop
6:46 pm - 11:44 pmSTL-ONT
6h 58m1 stop
$108Frontier
Find Deal
Thu, Dec 5 - Sat, Dec 7
10:11 pm - 7:34 pmONT-STL
19h 23m1 stop
6:46 pm - 11:44 pmSTL-ONT
6h 58m1 stop
$118Frontier
Find Deal
Wed, Dec 4 - Sat, Dec 7
7:00 am - 3:30 pmONT-STL
6h 30m1 stop
7:40 am - 12:26 pmSTL-ONT
6h 46m1 stop
$306Delta
Find Deal
Sat, Jan 18 - Tue, Jan 21
6:10 am - 6:23 pmONT-STL
10h 13m2 stops
5:03 am - 9:56 amSTL-ONT
6h 53m1 stop
$311American Airlines
Find Deal
Sat, Jan 18 - Tue, Jan 21
6:10 am - 7:23 pmONT-STL
11h 13m2 stops
11:38 am - 6:24 pmSTL-ONT
8h 46m2 stops
$316American Airlines
Find Deal
Sat, Jan 18 - Tue, Jan 21
6:00 am - 1:30 pmONT-STL
5h 30m1 stop
7:10 am - 12:08 pmSTL-ONT
6h 58m1 stop
$361Delta
Find Deal
Wed, Dec 18 - Wed, Dec 25
6:10 am - 4:38 pmONT-STL
8h 28m1 stop
4:31 pm - 8:47 pmSTL-ONT
6h 16m1 stop
$416United Airlines
Find Deal
Wed, Dec 11 - Thu, Dec 12
6:45 am - 3:15 pmONT-STL
6h 30m1 stop
6:35 am - 3:55 pmSTL-ONT
11h 20m1 stop
$428Southwest
Find Deal
Tue, Dec 10 - Thu, Dec 12
6:45 am - 5:05 pmONT-STL
8h 20m2 stops
1:00 pm - 10:10 pmSTL-ONT
11h 10m1 stop
$433Southwest
Find Deal
Tue, Dec 10 - Thu, Dec 12
1:42 pm - 10:16 pmONT-STL
6h 34m1 stop
4:36 pm - 8:51 pmSTL-ONT
6h 15m1 stop
$451United Airlines
Find Deal
Thu, Jan 2 - Tue, Jan 7
8:11 pm - 9:06 amONT-STL
10h 55m1 stop
$60Frontier
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Thu, Jan 9
4:08 pm - 8:13 amONT-STL
14h 05m1 stop
$62Frontier
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Thu, Dec 5
8:20 am - 6:10 pmONT-STL
7h 50m2 stops
$178Southwest
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Sun, Jan 12
6:10 am - 4:38 pmONT-STL
8h 28m1 stop
$198United Airlines
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Wed, Dec 11
5:50 am - 5:40 pmONT-STL
9h 50m2 stops
$202Delta
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Thu, Dec 12
5:05 am - 12:43 pmONT-STL
5h 38m1 stop
$218United Airlines
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Sun, Feb 16
6:20 am - 2:50 pmONT-STL
6h 30m2 stops
$243Southwest
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Fri, Dec 20
6:10 am - 7:28 pmONT-STL
11h 18m2 stops
$263American Airlines
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Wed, Dec 4
12:11 pm - 11:43 pmONT-STL
9h 32m1 stop
$289Delta
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Mon, Dec 9
12:59 am - 10:46 amONT-STL
7h 47m1 stop
$423American Airlines
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Sun, Dec 1
5:45 am - 12:06 amONT-STL
16h 21m1 stop
5:38 pm - 8:26 amSTL-ONT
16h 48m1 stop
$328Frontier
Find Deal
Fri, Nov 22 - Mon, Nov 25
5:45 am - 12:06 amONT-STL
16h 21m1 stop
5:38 pm - 12:04 amSTL-ONT
8h 26m1 stop
$353Frontier
Find Deal
Sun, Nov 24 - Tue, Nov 26
5:45 am - 12:06 amONT-STL
16h 21m1 stop
10:17 pm - 4:58 pmSTL-ONT
20h 41m1 stop
$398Frontier
Find Deal
Fri, Nov 22 - Sun, Nov 24
12:16 pm - 12:06 amONT-STL
9h 50m1 stop
10:17 pm - 4:58 pmSTL-ONT
20h 41m1 stop
$454Frontier
Find Deal
Sat, Nov 23 - Sun, Nov 24
5:00 pm - 12:42 amONT-STL
5h 42m1 stop
5:05 pm - 11:01 pmSTL-ONT
7h 56m1 stop
$477Delta
Find Deal
Tue, Nov 26 - Tue, Dec 3
5:05 am - 12:43 pmONT-STL
5h 38m1 stop
4:35 pm - 8:44 pmSTL-ONT
6h 09m1 stop
$836United Airlines
Find Deal
Tue, Nov 26 - Tue, Nov 26
10:00 am - 11:57 pmONT-STL
11h 57m2 stops
7:15 am - 8:00 pmSTL-ONT
14h 45m2 stops
$948Alaska Airlines
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Tue, Nov 26 - Tue, Dec 3
5:05 am - 12:43 pmONT-STL
5h 38m1 stop
4:35 pm - 8:44 pmSTL-ONT
6h 09m1 stop
$996United Airlines
Find Deal
Mon, Nov 25 - Mon, Nov 25
12:53 pm - 10:38 pmONT-STL
7h 45m2 stops
5:57 pm - 10:02 pmSTL-ONT
6h 05m1 stop
$1,011American Airlines
Find Deal
Fri, Nov 22 - Mon, Nov 25
2:22 pm - 11:59 pmONT-STL
7h 37m1 stop
7:15 am - 8:00 pmSTL-ONT
14h 45m2 stops
$1,057Alaska Airlines
Find Deal
Tue, Nov 26 - Tue, Dec 3

Delta flights from Ontario to St. Louis

Our best Delta deals on Ontario to St. Louis flight tickets
Delta
Jan 18
ONT7:00 amOntario
6h 30m
1 stop
STL3:30 pmLambert-St Louis
Jan 21
STL7:40 amLambert-St Louis
6h 46m
1 stop
ONT12:26 pmOntario
Delta
Dec 18
ONT6:00 amOntario
5h 30m
1 stop
STL1:30 pmLambert-St Louis
Dec 25
STL7:10 amLambert-St Louis
6h 58m
1 stop
ONT12:08 pmOntario
Delta
Dec 30
ONT1:15 pmOntario
6h 19m
1 stop
STL9:34 pmLambert-St Louis
Jan 6
STL7:40 amLambert-St Louis
6h 46m
1 stop
ONT12:26 pmOntario

American Airlines flights from Ontario to St. Louis

Our best American Airlines deals on Ontario to St. Louis flight tickets
American Airlines
Jan 18
ONT6:10 amOntario
10h 13m
2 stops
STL6:23 pmLambert-St Louis
Jan 21
STL5:03 amLambert-St Louis
6h 53m
1 stop
ONT9:56 amOntario
American Airlines
Jan 18
ONT6:10 amOntario
11h 13m
2 stops
STL7:23 pmLambert-St Louis
Jan 21
STL11:38 amLambert-St Louis
8h 46m
2 stops
ONT6:24 pmOntario
American Airlines
Jan 24
ONT6:10 amOntario
8h 10m
2 stops
STL4:20 pmLambert-St Louis
Jan 26
STL11:38 amLambert-St Louis
8h 46m
2 stops
ONT6:24 pmOntario

See travel insights to St. Louis from

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

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

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

June. The cheapest time of year to fly to St. Louis from Ontario is June. Most expensive is December

What is the cheapest day to depart Ontario for St. Louis?

Tuesday. The cheapest day of the week is typically Tuesday. The most expensive is typically Sunday

When is the cheapest time to fly from Ontario to St. Louis?

In the evening. Ontario to St. Louis flights are approximately 48% more expensive in the afternoon than in the evening

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

Ontario - Lambert-St Louis. Fly from Ontario to Lambert-St Louis for the best Ontario - St. Louis flight prices

How far in advance should you book Ontario to St. Louis flights?

53 days before. The cheapest time to buy a flight from Ontario to St. Louis is approximately 53 days to departure

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

You could potentially save up to 67% on your flight if you consider stops on a Ontario to St. Louis flight.

How have Ontario to St. Louis flight prices changed over time?

As of November 2024, prices for Ontario to St. Louis flights are approximately 14% more expensive when compared to flights at the same time last year.

When to book flights from Ontario to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to St. Louis (ONT to STL) flight deals and tips

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

Best Price Found

$60

Fastest flight time

5h 09m

Direct flights

None

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Ontario in the past 72 hours is $60. The best round-trip flight deal from Ontario to St. Louis found on momondo in the last 72 hours is $108.
The fastest flight from Ontario to St. Louis takes 5h 09m
There are no direct flights from Ontario to St. Louis. Popular non-direct route for this connection is Ontario Airport - Lambert-St Louis Airport.
There is 1 airport near St. Louis: Lambert-St Louis (STL)

  • How far is Ontario to Lambert-St Louis by plane?

    There are 1552.8 mi between Ontario and Lambert-St Louis. 5h 14m is a normal flight duration for this route.

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

    Prices for flights from Ontario Airport to Lambert-St Louis Airport are updated daily.

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Ontario Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The necessary travel and health documents for your Lambert-St Louis Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Ontario to St. Louis?


Best airlines flying from Ontario to St. Louis

Compare and see reviews for airlines that fly from Ontario to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $105Free CancellationRating
6.1
3,539 reviews
Search Frontier flights
DeltaPriceFrom $276Free CancellationRating
8.0
8,759 reviews
Search Delta flights
American AirlinesPriceFrom $282Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $288Free CancellationRating
7.4
9,173 reviews
Search United Airlines flights
SouthwestPriceFrom $326Free CancellationRating
8.1
5,015 reviews
Search Southwest flights
  • United Airlines Flights From Ontario to St. Louis

    United Airlines operates around 6 flights from Ontario to St. Louis every week. The average price of these flights found in the last 72 hours has been $481, but momondo users have found United Airlines deals from Ontario to St. Louis from as low as $288 round-trip. United Airlines has been scored 7.4/10 in 9,172 reviews.


Why use momondo?

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

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to St. Louis. momondo saves you time and could save you money on your trip.

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

Yes. momondo allows you to filter the results for Ontario to St. Louis flights to just show those with flexible booking policies.

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

Once all potential Ontario to St. Louis flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

If you are not ready to book a flight from Ontario to St. Louis now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to St. Louis and let you know when they change.


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