Find Cheap Flights from Lambert-St Louis to Ontario (STL - ONT)

Depart
Return
1 adult
Adults
18-64
Seniors
65+
Youths
12-17
Children
2-11
Seat Infants
under 2
Lap Infants
under 2
The price shown for each flight will be the average for all passengers including any infants.
Compare vs. KAYAK all | none
Browse Origins:
Browse Destinations:

Dates flexible? Here are the best fares found in the past 48 hours...

Book cheap flights from Lambert-St Louis to Ontario

(Round-trip)
Depart: Sat Sep 16 2017 Return: Sat Sep 23 2017 Trip spans 8 days
American Airlines
American Airlines
STL
2:15a
ONT
7:57a
5h 42m
1 stop
ONT
2:05a
STL
2:26p
12h 21m
1 stop
Depart: Tue May 16 2017 Return: Tue May 23 2017 Trip spans 8 days
Delta
Delta
STL
1:45a
ONT
7:31a
5h 46m
1 stop
ONT
12:46p
STL
6:09p
5h 23m
1 stop
Depart: Thu May 25 2017 Return: Sun May 28 2017 Trip spans 4 days
Major Airline
Major Airline
STL
1:00a
ONT
6:05a
5h 05m
1 stop
ONT
1:00a
STL
2:05a
1h 05m
1 stop
Depart: Thu Jun 15 2017 Return: Tue Jun 20 2017 Trip spans 6 days
United
United
STL
2:55a
ONT
10:12a
7h 17m
1 stop
ONT
1:35a
STL
9:37a
8h 02m
1 stop
Depart: Sun May 14 2017 Return: Mon May 15 2017 Trip spans 2 days
American Airlines
American Airlines
STL
3:20a
ONT
9:41a
6h 21m
1 stop
ONT
9:15p
STL
2:50a
5h 35m
1 stop
Depart: Thu May 18 2017 Return: Sun May 21 2017 Trip spans 4 days
Delta
Delta
STL
1:45a
ONT
7:31a
5h 46m
1 stop
ONT
12:46p
STL
6:09p
5h 23m
1 stop
Depart: Thu Jun 8 2017 Return: Mon Jun 26 2017 Trip spans 19 days
Major Airline
Major Airline
STL
9:48a
ONT
4:23a
18h 35m
2 stops
ONT
10:20p
STL
8:17a
9h 57m
2 stops
Depart: Sat Jun 24 2017 Return: Wed Jun 28 2017 Trip spans 5 days
United
United
STL
2:55a
ONT
10:12a
7h 17m
1 stop
ONT
1:35a
STL
9:37a
8h 02m
1 stop
Depart: Fri May 19 2017 Return: Sun May 21 2017 Trip spans 3 days
Delta
Delta
STL
1:45a
ONT
7:31a
5h 46m
1 stop
ONT
12:46p
STL
6:09p
5h 23m
1 stop
Depart: Mon May 8 2017 Return: Sat May 13 2017 Trip spans 6 days
American Airlines
American Airlines
STL
3:15p
ONT
9:20p
6h 05m
1 stop
ONT
2:20a
STL
8:30a
6h 10m
1 stop
Depart: Wed Jun 14 2017 Return: Mon Jun 19 2017 Trip spans 6 days
Major Airline
Major Airline
STL
10:30p
ONT
4:16p
17h 46m
2 stops
ONT
10:20p
STL
8:17a
9h 57m
2 stops
Depart: Sat Jul 1 2017 Return: Sun Jul 2 2017 Trip spans 2 days
United
United
STL
3:21p
ONT
10:09p
6h 48m
1 stop
ONT
1:25a
STL
6:56a
5h 31m
1 stop
Depart: Wed May 24 2017 Return: Sat May 27 2017 Trip spans 4 days
Delta
Delta
STL
1:45a
ONT
7:31a
5h 46m
1 stop
ONT
2:00a
STL
7:32a
5h 32m
1 stop
Depart: Sun Jul 2 2017 Return: Mon Jul 3 2017 Trip spans 2 days
United
United
STL
3:25a
ONT
10:38a
7h 13m
1 stop
ONT
1:25a
STL
9:38a
8h 13m
1 stop
Depart: Fri Aug 11 2017 Return: Sun Aug 13 2017 Trip spans 3 days
American Airlines
American Airlines
STL
10:40a
ONT
4:26p
5h 46m
1 stop
ONT
3:35p
STL
10:51p
7h 16m
1 stop
Depart: Thu Oct 12 2017 Return: Thu Oct 19 2017 Trip spans 8 days
Major Airline
Major Airline
STL
10:35p
ONT
10:30a
11h 55m
2 stops
ONT
10:20p
STL
8:08a
9h 48m
2 stops
Depart: Sat May 27 2017 Return: Mon May 29 2017 Trip spans 3 days
Delta
Delta
STL
2:30a
ONT
10:13a
7h 43m
1 stop
ONT
12:46p
STL
6:09p
5h 23m
1 stop
Depart: Mon Jul 3 2017 Return: Wed Jul 5 2017 Trip spans 3 days
United
United
STL
12:32p
ONT
6:40p
6h 08m
1 stop
ONT
1:25a
STL
9:38a
8h 13m
1 stop
Depart: Tue Sep 26 2017 Return: Sat Sep 30 2017 Trip spans 5 days
American Airlines
American Airlines
STL
10:30a
ONT
4:28p
5h 58m
1 stop
ONT
5:55a
STL
11:14a
5h 19m
1 stop
Depart: Fri Jun 2 2017 Return: Mon Jun 5 2017 Trip spans 4 days
Delta
Delta
STL
1:45a
ONT
7:31a
5h 46m
1 stop
ONT
12:46p
STL
6:09p
5h 23m
1 stop
* Prices are per person and are for e–tickets and include all taxes & fees in USD.

We attempt to get accurate prices, however, prices are not guaranteed.

Here's why:

We’re not the seller.
At KAYAK we don’t set the prices, so it’s not possible for us to guarantee what other companies are selling.

We compile tonnes of data for you
Our service lets you quickly and easily compare results from hundreds of travel sites at once. In this sense, KAYAK is a search engine and we can't guarantee prices we find.

Why aren’t prices accurate 100% of the time?
Prices on airline seats, hotel rooms and car rentals can change frequently. Several people may also be trying to buy the same travel option simultaneously. As a result, you may find, on occasion, that certain prices are no longer available.

If you have more questions or if you have a bad price to report to us,
please send us an email and someone from our team will get back to you promptly.

Airports
Origin

St. Louis
$412
Destination

Ontario
$412