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

ONT — STL
Dec 13 — Dec 201

The best prices from Ontario to Lambert-St Louis are usually found in December or February, booked 26 days in advance, depart on a Wednesday or Tuesday and return on a Monday

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

All the information you need to plan the best ONT to STL flight in 2022: compare Ontario to St. Louis flight prices with the expected peak season, weather and rainfall in St. Louis.

ONT - STL

Price

$272 - $650

STL

Temperature

32 - 80.6 °F

STL

Rainfall

2.2 - 4.7 inches

Popular inJulyHigh demand for flights, 37% potential price rise
Cheapest inDecemberBest time to find cheap flights, 34% potential price drop
Round-trip from$272From Ontario to Lambert-St Louis
One-way from$181One-way flight from Ontario to Lambert-St Louis

What is the cheapest day to fly round-trip from Ontario to St. Louis?

Leaving on a Tuesday is a viable option for saving on travel. Heavily demanded days of the week can typically drive up the prices you see. Booking your travel for a less competitive day can save up to 45% on the overall cost on flights from Ontario to St. Louis.

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

Users have found that booking a flight from Ontario to St. Louis at least 57 days early can save you up to 27% on average compared to booking a flight this week. If booking 57 days before your flight isn’t an option for you, users have found flights from Ontario to St. Louis for as little as $383 when booking for a departure date within the next two weeks. You can also check prices now. Some users have found airline tickets as low as $437 for flights departing within the next 3 days.

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

The best pricing can be found in the month of February. Prices to St. Louis from Ontario average $347. You can even find prices in February for less than $347, as users have found deals to St. Louis from as low as $81. The month of July appears to be one of the more expensive times to travel to St. Louis from Ontario. Flying in the targeted month can save you up to 50%.

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 evening. If you’re flexible enough to do this you can expect to save up to 36% on your trip compared to booking a flight in the morning.

Cheap flights from Ontario to St. Louis in December, January 2022

The best prices found for ONT to STL flights for December, January
Dec 24 - Jan 3
ONT

Ontario

STL

Lambert-St Louis

1 stop

11h 16m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 29m
$160

Frontier

Pick Dates

Deal found 12/6

Dec 11 - Dec 15
ONT

Ontario

STL

Lambert-St Louis

1 stop

6h 07m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 58m
$165

Frontier

Pick Dates

Deal found 12/7

Dec 11 - Dec 13
ONT

Ontario

STL

Lambert-St Louis

1 stop

6h 07m
STL

Lambert-St Louis

ONT

Ontario

1 stop

20h 38m
$166

Frontier

Pick Dates

Deal found 12/7

Ontario to St. Louis 2022 flight deals

Cheap flights to St. Louis from Ontario found for this year
Dec 24 - Jan 3
ONT

Ontario

STL

Lambert-St Louis

1 stop

11h 16m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 29m
$160

Frontier

Pick Dates

Deal found 12/6

Dec 11 - Dec 15
ONT

Ontario

STL

Lambert-St Louis

1 stop

6h 07m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 58m
$165

Frontier

Pick Dates

Deal found 12/7

Dec 11 - Dec 13
ONT

Ontario

STL

Lambert-St Louis

1 stop

6h 07m
STL

Lambert-St Louis

ONT

Ontario

1 stop

20h 38m
$166

Frontier

Pick Dates

Deal found 12/7

Cheap Frontier flights from Ontario to St. Louis

Dec 24 - Jan 3
ONT

Ontario

STL

Lambert-St Louis

1 stop

11h 16m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 29m
$160

Frontier

Pick Dates

Deal found 12/6

Dec 15 - Jan 9
ONT

Ontario

STL

Lambert-St Louis

1 stop

10h 25m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 27m
$165

Frontier

Pick Dates

Deal found 12/7

Jan 26 - Jan 29
ONT

Ontario

STL

Lambert-St Louis

1 stop

18h 00m
STL

Lambert-St Louis

ONT

Ontario

1 stop

10h 57m
$168

Frontier

Pick Dates

Deal found 12/5

Cheap United Airlines flights from Ontario to St. Louis

Dec 14 - Jan 6
ONT

Ontario

STL

Lambert-St Louis

2 stops

15h 07m
STL

Lambert-St Louis

ONT

Ontario

2 stops

16h 12m
$433

United Airlines

Pick Dates

Deal found 12/7

Dec 14 - Jan 6
ONT

Ontario

STL

Lambert-St Louis

1 stop

9h 05m
STL

Lambert-St Louis

ONT

Ontario

2 stops

12h 09m
$468

United Airlines

Pick Dates

Deal found 12/7

Dec 13 - Jan 5
ONT

Ontario

STL

Lambert-St Louis

1 stop

5h 06m
STL

Lambert-St Louis

ONT

Ontario

2 stops

12h 09m
$504

United Airlines

Pick Dates

Deal found 12/6

Last minute flights from Ontario to St. Louis

Late deals on return flights to St. Louis from Ontario, departing today and this week
Dec 15 - Jan 9
ONT

Ontario

STL

Lambert-St Louis

1 stop

10h 25m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 27m
$165

Frontier

Pick Dates

Deal found 12/7

Dec 13 - Feb 8
ONT

Ontario

STL

Lambert-St Louis

1 stop

12h 16m
STL

Lambert-St Louis

ONT

Ontario

1 stop

11h 32m
$168

Frontier

Pick Dates

Deal found 12/5

Dec 14 - Jan 10
ONT

Ontario

STL

Lambert-St Louis

1 stop

11h 24m
STL

Lambert-St Louis

ONT

Ontario

1 stop

21h 58m
$170

Frontier

Pick Dates

Deal found 12/6

One-way flights to St. Louis from Ontario

The cheapest one-way flights from Ontario to St. Louis
Dec 14
ONT

Ontario

STL

Lambert-St Louis

1 stop

11h 24m
$77

Frontier

Pick Dates

Deal found 12/5

Dec 15
ONT

Ontario

STL

Lambert-St Louis

1 stop

6h 07m
$81

Frontier

Pick Dates

Deal found 12/5

Dec 13
ONT

Ontario

STL

Lambert-St Louis

1 stop

9h 06m
$84

Frontier

Pick Dates

Deal found 12/6

Related info for your journey

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

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 Delta. 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 $160, but on average you can expect to pay $197.

Are there last-minute flights available from Ontario to St. Louis for under $200?

There are currently 20+ open flights from Ontario to St. Louis within the next 7 days for less than $200.

How popular is this Ontario to St. Louis flight route?

Within the past month, 12 users have taken a look at flights from Ontario to Lambert-St Louis.

What is the cheapest airline to fly from Ontario to St. Louis round-trip?

Flying on Frontier is currently your cheapest option to St. Louis, with prices starting at $160. Frontier is priced at 60% lower than the current average price of a flight leaving 3 months from now.

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

The cheapest airlines for a one-way flight from Ontario to St. Louis are Frontier ($77), United Airlines ($158), and Delta ($188).

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

Before booking your flight from Ontario to St. Louis check out the most popular airlines for this route: American Airlines, Alaska Airlines or Delta.

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

Looking for the cheapest flight from Ontario to St. Louis? While on average our users pay $1,069, our data indicates the cheapest price to be $84. The most popular route (Ontario - Lambert-St Louis), is priced around $163.

Alternative routes for Ontario to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.

Top 5 airlines flying 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.
AirlineCheapestAverageFlexibilityOn-timeCOVID-19 safety
Juneyao AirlinesCheapest$14Average$22FlexibilityNo cancel feeOn-time66%COVID-19 safety
Search Juneyao Airlines flights
FrontierCheapest$140Average$265FlexibilityNo cancel feeOn-time62%COVID-19 safety
Search Frontier flights
United AirlinesCheapest$197Average$453FlexibilityNo cancel feeOn-time69%COVID-19 safety
Search United Airlines flights
DeltaCheapest$255Average$442FlexibilityNo cancel feeOn-timeN/ACOVID-19 safety
Search Delta flights
American AirlinesCheapest$269Average$586FlexibilityNo cancel feeOn-time71%COVID-19 safety
Search American Airlines flights