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Cheap flights from St. Louis to Ontario from $52

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 12/7. 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 St. Louis to Los Angeles

Cheap round-trip flights

These are some of the best round-trip flight deals from St. Louis to Los Angeles 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 St. Louis to Los Angeles.

Cheap last minute flights

Planning a quick getaway from St. Louis to Los Angeles? 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 Los Angeles, so you can enjoy a seamless trip without layovers.

Cheap bus & train deals from St. Louis to Los Angeles

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

All round-trip flight deals to Los Angeles

The cheapest plane tickets to Los Angeles found on KAYAK recently.
6:46 pm - 11:44 pmSTL-ONT
6h 58m1 stop
6:45 am - 8:13 amONT-STL
23h 28m1 stop
$118Frontier
Find Deal
Sat, Dec 7 - Thu, Dec 12
6:53 pm - 12:09 amSTL-ONT
7h 16m1 stop
12:59 am - 9:16 amONT-STL
6h 17m1 stop
$124Frontier
Find Deal
Wed, Feb 19 - Tue, Feb 25
5:00 pm - 11:53 pmSTL-ONT
8h 53m1 stop
1:21 pm - 9:33 pmONT-STL
6h 12m1 stop
$306Delta
Find Deal
Tue, Jan 14 - Wed, Jan 22
2:29 pm - 6:27 pmSTL-ONT
5h 58m1 stop
10:02 am - 7:30 pmONT-STL
7h 28m2 stops
$311American Airlines
Find Deal
Tue, Dec 17 - Tue, Dec 24
5:21 am - 9:56 amSTL-ONT
6h 35m1 stop
4:25 pm - 11:57 pmONT-STL
5h 32m1 stop
$316American Airlines
Find Deal
Sat, Jan 4 - Wed, Jan 8
7:20 am - 12:25 pmSTL-ONT
7h 05m1 stop
1:21 pm - 9:33 pmONT-STL
6h 12m1 stop
$326Delta
Find Deal
Mon, Dec 16 - Tue, Jan 7
5:10 pm - 10:20 pmSTL-ONT
7h 10m1 stop
8:20 am - 6:10 pmONT-STL
7h 50m2 stops
$358Southwest
Find Deal
Fri, Jan 10 - Sun, Jan 12
6:05 am - 10:55 amSTL-ONT
6h 50m1 stop
9:40 am - 7:30 pmONT-STL
7h 50m2 stops
$382Southwest
Find Deal
Wed, Dec 18 - Fri, Jan 3
4:45 pm - 9:42 pmSTL-ONT
6h 57m1 stop
5:05 am - 12:48 pmONT-STL
5h 43m1 stop
$406United Airlines
Find Deal
Tue, Dec 17 - Wed, Jan 1
4:45 pm - 9:42 pmSTL-ONT
6h 57m1 stop
5:05 am - 12:43 pmONT-STL
5h 38m1 stop
$416United Airlines
Find Deal
Fri, Dec 13 - Sat, Dec 14
6:46 pm - 11:44 pmSTL-ONT
6h 58m1 stop
$52Frontier
Find Deal
Sat, Dec 7
6:46 pm - 11:44 pmSTL-ONT
6h 58m1 stop
$53Frontier
Find Deal
Sat, Dec 7
7:20 am - 12:25 pmSTL-ONT
7h 05m1 stop
$153Delta
Find Deal
Tue, Dec 10
9:39 am - 6:27 pmSTL-ONT
10h 48m2 stops
$158American Airlines
Find Deal
Tue, Dec 17
5:21 am - 9:56 amSTL-ONT
6h 35m1 stop
$163American Airlines
Find Deal
Sat, Jan 4
6:30 pm - 12:14 amSTL-ONT
7h 44m1 stop
$173Delta
Find Deal
Fri, Dec 13
4:30 pm - 9:59 pmSTL-ONT
7h 29m1 stop
$218United Airlines
Find Deal
Sun, Feb 16
8:00 am - 8:51 pmSTL-ONT
14h 51m2 stops
$222United Airlines
Find Deal
Sat, Jan 11
11:45 am - 5:35 pmSTL-ONT
7h 50m2 stops
$234Southwest
Find Deal
Sun, Dec 15
9:40 am - 1:10 pmSTL-ONT
5h 30m1 stop
$439Southwest
Find Deal
Sun, Dec 1
5:38 pm - 12:04 amSTL-ONT
8h 26m1 stop
10:11 pm - 7:34 pmONT-STL
19h 23m1 stop
$228Frontier
Find Deal
Mon, Nov 25 - Wed, Dec 4
7:41 pm - 11:47 pmSTL-ONT
6h 06m1 stop
11:45 am - 7:20 pmONT-STL
5h 35m1 stop
$236Frontier
Find Deal
Mon, Nov 25 - Thu, Dec 19
5:17 am - 9:47 amSTL-ONT
6h 30m1 stop
12:59 am - 10:46 amONT-STL
7h 47m1 stop
$646American Airlines
Find Deal
Tue, Nov 26 - Sun, Dec 1
7:15 am - 12:03 pmSTL-ONT
6h 48m1 stop
12:53 pm - 10:38 pmONT-STL
7h 45m2 stops
$651American Airlines
Find Deal
Tue, Nov 26 - Mon, Dec 2
8:40 am - 12:40 pmSTL-ONT
6h 00m1 stop
6:00 am - 12:43 pmONT-STL
28h 43m2 stops
$781United Airlines
Find Deal
Mon, Nov 25 - Wed, Dec 4
7:09 am - 1:00 pmSTL-ONT
7h 51m1 stop
6:28 pm - 8:41 pmONT-STL
24h 13m3 stops
$815United Airlines
Find Deal
Mon, Nov 25 - Wed, Dec 4
7:00 am - 1:27 pmSTL-ONT
8h 27m1 stop
8:32 pm - 11:59 pmONT-STL
25h 27m2 stops
$864Alaska Airlines
Find Deal
Sun, Nov 24 - Thu, Jan 2
6:00 am - 4:45 pmSTL-ONT
12h 45m2 stops
11:18 am - 12:42 amONT-STL
11h 24m2 stops
$899Delta
Find Deal
Fri, Nov 22 - Mon, Nov 25
2:23 pm - 11:59 pmSTL-ONT
11h 36m1 stop
8:19 pm - 11:59 pmONT-STL
25h 40m2 stops
$942Alaska Airlines
Find Deal
Fri, Nov 22 - Mon, Nov 25
2:25 pm - 10:45 pmSTL-ONT
10h 20m2 stops
1:18 pm - 10:45 pmONT-STL
7h 27m2 stops
$1,367Delta
Find Deal
Sat, Nov 23 - Sat, Nov 30

Frontier flights from St. Louis to Ontario

Our best Frontier deals on St. Louis to Ontario flight tickets
Frontier
Dec 7
STL6:46 pmLambert-St Louis
6h 58m
1 stop
ONT11:44 pmOntario
Dec 12
ONT6:45 amOntario
23h 28m
1 stop
STL8:13 amLambert-St Louis
Frontier
Feb 19
STL6:53 pmLambert-St Louis
7h 16m
1 stop
ONT12:09 amOntario
Feb 25
ONT12:59 amOntario
6h 17m
1 stop
STL9:16 amLambert-St Louis
Frontier
Dec 18
STL6:49 pmLambert-St Louis
7h 10m
1 stop
ONT11:59 pmOntario
Jan 6
ONT1:05 pmOntario
5h 24m
1 stop
STL8:29 pmLambert-St Louis

Delta flights from St. Louis to Ontario

Our best Delta deals on St. Louis to Ontario flight tickets
Delta
Jan 14
STL5:00 pmLambert-St Louis
8h 53m
1 stop
ONT11:53 pmOntario
Jan 22
ONT1:21 pmOntario
6h 12m
1 stop
STL9:33 pmLambert-St Louis
Delta
Dec 16
STL7:20 amLambert-St Louis
7h 05m
1 stop
ONT12:25 pmOntario
Jan 7
ONT1:21 pmOntario
6h 12m
1 stop
STL9:33 pmLambert-St Louis
Delta
Dec 15
STL6:00 amLambert-St Louis
12h 54m
2 stops
ONT4:54 pmOntario
Dec 18
ONT6:00 amOntario
5h 30m
1 stop
STL1:30 pmLambert-St Louis

See travel insights to Los Angeles from

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

What is the cheapest month to fly to Ontario?

In general, April is the cheapest month to fly from St. Louis to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $176. If you aren’t able to travel during the month of April, then book flights to Ontario from St. Louis during June instead. Flights to Ontario in June, while not as cheap as those in April, still average around $217.

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

The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $286. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Ontario for around $426.

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

In the evening is the cheapest time of day to fly from St. Louis to Ontario when you can find flight prices for as low as $214. Flying to Ontario in the evening is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $441 on average. Flights to Ontario from St. Louis in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

How far in advance should I book a flight to Ontario?

Most flyers found that booking tickets 16 days in advance of their planned departure date is the best time to get cheap flights to Ontario. During this timeframe, flight prices are around $338. However, in the past 72 hours, people saw flights from St. Louis for as low as $136.

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

You could potentially save up to 66% on your flight if you consider stops on a St. Louis to Ontario flight.

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

As of November 2024, prices for St. Louis to Ontario flights are approximately 30% cheaper when compared to flights at the same time last year.

When to book flights from St. Louis to Ontario

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

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

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

Best Price Found

$52

Fastest flight time

5h 30m

Direct flights

None

Airports in Ontario

1 airport
The best one-way flight to Ontario from St. Louis in the past 72 hours is $52. The best round-trip flight deal from St. Louis to Ontario found on momondo in the last 72 hours is $118.
The fastest flight from St. Louis to Ontario takes 5h 30m
There are no direct flights from St. Louis to Ontario. Popular non-direct route for this connection is Lambert-St Louis Airport - Ontario Airport.
There is 1 airport near Ontario: Ontario (ONT)

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

    A flight from Lambert-St Louis to Ontario will travel around 1552.8 mi. 5h 39m is a normal flight duration for this route.

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

    Prices for flights from Lambert-St Louis Airport to Ontario Airport are refreshed on a daily basis.

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

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

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Ontario Airport.

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

    The required travel and health documents for your Ontario Airport 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 Airport. 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 Ontario?

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


Best airlines flying from St. Louis to Ontario

Compare and see reviews for airlines that fly from St. Louis to Ontario with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $123Free CancellationRating
6.1
3,536 reviews
Search Frontier flights
American AirlinesPriceFrom $281Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
DeltaPriceFrom $286Free CancellationRating
8.0
8,755 reviews
Search Delta flights
United AirlinesPriceFrom $326Free CancellationRating
7.4
9,172 reviews
Search United Airlines flights
SouthwestPriceFrom $326Free CancellationRating
8.1
5,005 reviews
Search Southwest flights

Why use momondo?

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

Finding the right flight to Ontario from St. Louis is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Ontario quick and easy, saving you time and money.

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

Yes. momondo enables you to select and highlight flights to Ontario from St. Louis with this policy.

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

momondo helps you find the best flight between St. Louis and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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.


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