Find Cheap Flights from Ontario to United States

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 Ontario to United States

(Round-trip)
Depart: Fri Sep 8 2017 Return: Mon Sep 11 2017 Trip spans 4 days
Major Airline
Major Airline
ONT
SFO
7h 31m
nonstop
SFO
ONT
6h 50m
nonstop
Depart: Wed May 17 2017 Return: Sun May 21 2017 Trip spans 5 days
United
United
ONT
SFO
1h 30m
nonstop
SFO
ONT
1h 26m
nonstop
Depart: Tue Jun 6 2017 Return: Wed Jun 7 2017 Trip spans 2 days
Delta
Delta
ONT
SLC
1h 49m
nonstop
SLC
ONT
1h 51m
nonstop
Depart: Wed Oct 18 2017 Return: Sat Oct 21 2017 Trip spans 4 days
Alaska Airlines
Alaska Airlines
ONT
PDX
2h 21m
nonstop
PDX
ONT
2h 18m
nonstop
Depart: Tue May 9 2017 Return: Sat May 13 2017 Trip spans 5 days
American Airlines
American Airlines
ONT
BOI
9h 36m
1 stop
BOI
ONT
9h 03m
1 stop
Depart: Thu May 18 2017 Return: Sat May 20 2017 Trip spans 3 days
Major Airline
Major Airline
ONT
SFO
5h 52m
nonstop
SFO
ONT
7h 05m
nonstop
Depart: Mon May 22 2017 Return: Thu May 25 2017 Trip spans 4 days
Major Airline
Major Airline
ONT
SFO
5h 36m
nonstop
SFO
ONT
4h 40m
nonstop
Depart: Thu Jun 1 2017 Return: Mon Jun 5 2017 Trip spans 5 days
United
United
ONT
SFO
1h 30m
nonstop
SFO
ONT
1h 26m
nonstop
Depart: Tue Jul 11 2017 Return: Wed Jul 12 2017 Trip spans 2 days
United
United
ONT
SFO
1h 30m
nonstop
SFO
ONT
1h 29m
nonstop
Depart: Sat Jun 3 2017 Return: Tue Jun 6 2017 Trip spans 4 days
American Airlines
American Airlines
ONT
BOI
15h 58m
1 stop
BOI
ONT
20h 22m
1 stop
Depart: Fri Jun 2 2017 Return: Sat Jun 3 2017 Trip spans 2 days
Major Airline
Major Airline
ONT
SFO
5h 42m
nonstop
SFO
ONT
16h 26m
nonstop
Depart: Fri Aug 11 2017 Return: Mon Aug 14 2017 Trip spans 4 days
United
United
ONT
SFO
1h 30m
nonstop
SFO
ONT
1h 29m
nonstop
Depart: Sat Jul 29 2017 Return: Wed Aug 2 2017 Trip spans 5 days
Alaska Airlines
Alaska Airlines
ONT
PDX
2h 18m
nonstop
PDX
ONT
2h 15m
nonstop
Depart: Tue Jul 11 2017 Return: Tue Jul 18 2017 Trip spans 8 days
American Airlines
American Airlines
ONT
BOI
9h 33m
1 stop
BOI
ONT
20h 22m
1 stop
Depart: Fri Aug 18 2017 Return: Sun Aug 20 2017 Trip spans 3 days
Major Airline
Major Airline
ONT
SFO
0h 43m
nonstop
SFO
ONT
0h 43m
nonstop
Depart: Tue Oct 3 2017 Return: Tue Oct 10 2017 Trip spans 8 days
Delta
Delta
ONT
SEA
6h 20m
1 stop
SEA
ONT
4h 19m
1 stop
Depart: Sat Aug 12 2017 Return: Mon Aug 28 2017 Trip spans 17 days
Alaska Airlines
Alaska Airlines
ONT
PDX
2h 18m
nonstop
PDX
ONT
2h 11m
nonstop
Depart: Thu Sep 7 2017 Return: Sun Sep 10 2017 Trip spans 4 days
Major Airline
Major Airline
ONT
SFO
5h 34m
nonstop
SFO
ONT
13h 55m
nonstop
Depart: Fri Sep 29 2017 Return: Tue Oct 3 2017 Trip spans 5 days
American Airlines
American Airlines
ONT
DFW
6h 19m
1 stop
DFW
ONT
3h 07m
nonstop
Depart: Thu Jun 22 2017 Return: Tue Jun 27 2017 Trip spans 6 days
United
United
ONT
SFO
1h 25m
nonstop
SFO
ONT
1h 29m
nonstop
* 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

Ontario
$107
Destination

San Francisco
$107
Portland
$177
Seattle
$214
Boise
$184
Salt Lake City
$149
Dallas
$191