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Cheap flights from Ontario to St Louis (ONT - STL)

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The best prices from Ontario to St Louis are usually found in September or August, booked 41 days in advance, depart on a Tuesday or Wednesday and return on a Tuesday

How to find the cheapest flight from
Ontario (ONT) to St Louis (STL)

ONT - STL
Price
$232 - $428
STL
Temperature
44.6 - 89.6 °F
STL
Rainfall
2.2 - 5.1 inches

Popular in

December

High demand for flights, 22% potential price rise

Cheapest in

September

Best time to find cheap flights, 31% potential price drop

Round-trip from

$232

From Ontario to St Louis

One-way from

$172

One-way flight from Ontario to St Louis

Flight route prices based on searches on Cheapflights within the last 3 days, monthly prices based on aggregated historical data.
What is the cheapest day to fly round-trip from Ontario to St Louis?

Flying to your destination on a Thursday can be more expensive, but this shouldn’t discourage you from finding affordable options to get to St Louis. Check prices with Cheapflights to find a great deal for your trip.

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

To save on the cost of your flight from Ontario to St Louis, book at least 31 days before your planned departure. Booking around this time can save you about 96% on the cost of this flight compared to booking a flight leaving this week. We have found prices from $374 if you need a flight within two weeks. For flights within the next 72 hours, you can find tickets from as low as $553.

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

Flights from Ontario to St Louis lean towards being more expensive in December. Prices are generally better when you fly from Ontario to St Louis in August, with the cheapest ticket starting at $158.

When is the cheapest time to fly from Ontario to St Louis (ONT - STL)?

A simple way to save on the total cost of your ticket is to fly from Ontario to St Louis in the afternoon. If you’re flexible enough to do this you can expect to save up to 32% on your trip compared to booking a flight in the morning.

Cheap flights from Ontario to St Louis in November, December 2020

The best prices found for ONT to STL flights for November, December
26 Dec - 3 Jan
$174pp
ONT
Ontario
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
ONT
Ontario
26 Dec - 3 Jan
$262pp
ONT
Ontario
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Multiple Airlines
     
3 STOPS
ONT
Ontario
28 Nov - 1 Dec
$265pp
ONT
Ontario
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
ONT
Ontario

Ontario to St Louis 2021 flight deals

Cheap flights to St Louis from Ontario found for next year
26 Dec - 3 Jan
$174pp
ONT
Ontario
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
ONT
Ontario
26 Dec - 3 Jan
$262pp
ONT
Ontario
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Multiple Airlines
     
3 STOPS
ONT
Ontario
28 Nov - 1 Dec
$265pp
ONT
Ontario
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
ONT
Ontario

Last minute flights from Ontario to St Louis

Late deals on round-trip flights to St Louis from Ontario, departing today and this week
5 Dec - 7 Dec
$342pp
ONT
Ontario
United Airlines
   
2 STOPS
STL
Lambert-St Louis
STL
Lambert-St Louis
United Airlines
 
1 STOP
ONT
Ontario
5 Dec - 7 Dec
$379pp
ONT
Ontario
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
United Airlines
 
1 STOP
ONT
Ontario

One-way flights to St Louis from Ontario

The cheapest one-way flights from Ontario to St Louis
12:30 pm - 6:29 am
Frontier
2 Stops
15h 59m
ONT - STL
Frontier
$172
Kiwi.com
6:15 pm - 5:03 am
Delta
1 Stop
8h 48m
ONT - STL
Delta
$203
Delta
1:00 am - 11:09 am
Multiple Airlines
3 Stops
32h 09m
ONT - STL
Multiple Airlines
$241
United

Related info for your journey

Useful info, stats and facts about Ontario to St Louis flights.

Flight FAQs

From Ontario to St Louis

Are flight prices decreasing from Ontario to St Louis due to COVID-19 (coronavirus)?

At this time, Cheapflights has noticed price decreases for many domestic flights due to COVID-19. Travel is not necessarily recommended at this time, and flights may be prone to cancellation: please check with local authorities in both Ontario and St Louis for travel alerts, and be sure to review the airline's cancellation policy and travel advisories before booking. For more information, please view our post on what to know about COVID-19 (coronavirus) and travel.

What safety measures are being taken by airlines flying from Ontario to Lambert-St Louis to control the spread of COVID-19?

Airlines globally have implemented additional safety measures to accommodate you. Delta is one of them. Some of the new policies that have been implemented to accommodate travelers flying from Ontario to Lambert-St Louis are improved sanitation, HEPA filters, mask requirements, social distance seating (for a limited time), and pre-flight testing for antibodies and symptoms. Policies will vary by airline.

Which airlines flying from Ontario to Lambert-St Louis have flexible cancellations due to COVID-19?

Some of the carriers operating flights from Ontario to Lambert-St Louis that may be offering flexible cancellation policies are American Airlines, Frontier, and United Airlines. Our site will let you filter for all airlines offering greater flexibility due to COVID-19.

Can I find flights from Ontario to St Louis for under $200 on Cheapflights?

Yes, there are multiple flights from Ontario to St Louis for under $200. The cheapest flight booked recently is on Frontier for just $174, but on average you can expect to pay $323.

Are there nonstop flights from Ontario to St Louis for under $200 on Cheapflights?

There are no nonstop flights from Ontario to St Louis, but Cheapflights can provide you with all the information you need to find the fastest route with the fewest stops.

Are there last-minute flights available from Ontario to St Louis for under $400?

There are currently 2+ open flights from Ontario to St Louis within the next 7 days for less than $400.

How popular is this flight route?

This flight path from Ontario to Lambert-St Louis was viewed by 283 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

Does it rain more in Ontario or St Louis?

In Ontario, there will be less rainfall in Ontario compared to St Louis over the next 4 days.

Is Ontario weather warmer or cooler than St Louis?

We forecast the temperature to be around the 95 °F's in July, on average. The temperature in St Louis is generally colder than in Ontario. Book flights in a timely manner in correlation to your departure date.

How long is the flight from Ontario to St Louis?

United Airlines, American Airlines, and Delta can get you from Ontario to St Louis in just under 5h 03m. Your travel time can differ by up to 3h 11m. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

What are the cheapest airlines flying from Ontario to St Louis round-trip?

According to our current data, Frontier ($174), Delta ($266), and United Airlines ($286) offers the cheapest pricing from Ontario to St Louis. Users have found that Frontier is 47% cheaper than the other options available to this destination.

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

The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $65. However, be on the lookout for offers from United Airlines and Delta, as they are both options that can get you from Ontario to St Louis for a low price.

Alternative routes for Ontario to St Louis

Destination information for St Louis

Things to know before you go. Useful info for your trip from Ontario to St Louis
Average temperature for November in St Louis
57.2 °F
Avg rainfall for November in St Louis
3.4 ″

Airports servicing Ontario

Airports servicing St. Louis

Top 4 airlines from Ontario to St Louis

The chart below displays the airlines Cheapflights users traveling from Ontario to St Louis choose most often. Cheapest and average prices are based on aggregated data from the past 12 months.

Airline Cheapest Average Flexibility On-time COVID-19 safety
Frontier
$104 $241 No cancel fee 62%
Delta
$149 $333 No cancel fee N/A
United Airlines
$159 $397 No cancel fee 69%
American Airlines
$159 $416 No cancel fee 71%

Hourly flight availability from Ontario to St Louis

Early morning Midnight to 6 AM 100% of ONT to STL departures
Morning 6 AM to noon 0% of ONT to STL departures
Afternoon Noon to 6 PM 0% of ONT to STL departures
Evening 6 PM to midnight 0% of ONT to STL departures
Midnight
6 AM
Noon
6 PM
Weekly flight availability
from Ontario to St Louis
Sunday
1 daily flight
Monday
1 daily flight
Tuesday
1 daily flight
Wednesday
1 daily flight
Thursday
0 flights
Friday
1 daily flight
Saturday
0 flights
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