Cheap Flight Tickets from Ontario (ONT) to St Louis (STL), Starting at $113

Good to Know: Cheapest and Fastest ONT - STL Flights

Useful information for finding best airline tickets from Ontario International to Lambert St Louis International on your next trip.

Cheapest Round Trip Flight

$113

WN Southwest Airlines • 2 stops • 15h 55m

Nov 10 – Nov 17

The cheapest round trip flight from Ontario to St Louis (ONT-STL-ONT) is currently $113

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Cheapest Direct Flight

$382

AA American Airlines • nonstop •

Nov 10

The cheapest nonstop flight from Ontario to St Louis (ONT-STL) is currently $382

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Fastest Flight

5h 25m

The fastest nonstop flight from Ontario to St Louis (ONT-STL) takes 5h 25m

Top Airlines Flying from Ontario to St Louis

Southwest Airlines-WN

Southwest Airlines

Delta Airline, DL

Delta Airlines

United Airlines, UA

United Airlines

American Airlines, AA

American Airlines

Alaska Airlines -AS

Alaska Airlines

Latest Flight Deals from Ontario (ONT) to St Louis (STL)

Compare and book low fare round-trip air tickets from Ontario to St Louis. Ideal for travelers with confirmed return itineraries.

Nov 10 - Nov 17, Economy
WN
Ontario → St Louis
15h 55m
10:05 AM - 10:00 PM • 2 stops
WN
Ontario → St Louis
11h 55m
2:35 PM - 7:50 PM • 2 stops
$113
Southwest Airlines
Nov 10 - Nov 17, Economy
WN
Ontario → St Louis
26h 55m
6:25 PM - 12:40 PM • 2 stops
WN
Ontario → St Louis
11h 55m
2:35 PM - 7:50 PM • 2 stops
$115
Southwest Airlines
Nov 10 - Nov 17, Economy
UA
Ontario → St Louis
- • 2 stops
UA
Ontario → St Louis
- • 1 stop
$302
United Airlines
Nov 10 - Nov 17, Economy
AS
Ontario → St Louis
40h 23m
12:02 PM - 2:25 PM • 1 stop
AS
Ontario → St Louis
18h 33m
6:00 AM - 3:13 PM • 1 stop
$608
Alaska Airlines
Nov 10 - Nov 17, Economy
WN
Ontario → St Louis
10h 55m
5:45 AM - 2:40 PM • 1 stop
WN
Ontario → St Louis
8h 40m
6:25 AM - 9:45 AM • 1 stop
$642
Southwest Airlines
Nov 10 - Nov 17, Economy
AA
Ontario → St Louis
11h 51m
2:22 PM - 11:33 PM • 1 stop
AA
Ontario → St Louis
9h 2m
2:28 PM - 6:10 PM • 1 stop
$658
American Airlines

Fly from Ontario to St Louis with the Best Airfare Deals on FareLeaders

Looking for a cheap last-minute deal or the best round-trip flight from Ontario to St Louis? Find the biggest savings on one-way and round-trip tickets right here.

FAQs on Ontario to St Louis Flights

What are the airports in Ontario?
ONT
What’s the most popular airline flying from ONT to STL?
The most popular airline flying from Ontario to St Louis are
Can I fly from ONT to STL non-stop?
Yes, you can fly ONT to STL non-stop on
Which airlines fly nonstop between Ontario and St Louis?
The non-stop flights between Ontario and St Louis are .
What’s the earliest departure time from ONT to STL Airport?
The earliest flight leaves ONT at 5:45 am and lands in STL - Lambert St Louis International
What are the airports in St Louis?
STL
Can I make changes to my Ontario to St Louis flight tickets or cancel them on FareLeaders.com?
No. We are an airfare comparison site. All the tickets are booked by the travel agent offering the flight deal and any changes or cancellations to be made are directly done directly by them or the airlines.
Can I cancel my flight tickets from ONT to STL?
Read the fare rules of the Ontario to St Louis air tickets booked. Some airlines allow you to cancel the tickets within a stipulated time period with a cancellation fee.
Which airline alliances offer flights from Ontario and St Louis?
operate flights between Ontario and St Louis
How long does a flight from Ontario to St Louis take?
It takes approximately 4 hour to fly non-stop from ONT to STL, which is 1545.85 miles by air.
Which airlines provide the cheapest flights from Ontario (ONT) to St Louis (STL) ?
In the past couple of days, the cheapest tickets to STL from ONT were found on UA : USD 302
Do I need a passport to fly between ONT and STL?
No
What’s the latest departure time from ONT to STL ?
The last flight leaves ONT at 3:0000 pm

Ontario (ONT) to St Louis (STL): Airport Information

Origin Airport Ontario International , Ontario, US
Destination Airport Lambert St Louis International , St Louis, US
Distance 1546 miles

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