Find Deals on International Flights to Ontario

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

Book cheap flights from worldwide to Ontario

(Round-trip)
Depart: Thu Oct 12 2017 Return: Wed Oct 18 2017 Trip spans 7 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Tue Oct 17 2017 Return: Sat Oct 21 2017 Trip spans 5 days
United
United
PDX
ONT
4h 04m
1 stop
ONT
PDX
5h 06m
1 stop
Depart: Tue Oct 10 2017 Return: Wed Oct 18 2017 Trip spans 9 days
Alaska Airlines
Alaska Airlines
PDX
ONT
2h 22m
nonstop
ONT
PDX
2h 23m
nonstop
Depart: Fri Oct 13 2017 Return: Sun Oct 15 2017 Trip spans 3 days
Multiple Airlines
Multiple Airlines
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 17m
nonstop
Depart: Thu Oct 12 2017 Return: Wed Oct 18 2017 Trip spans 7 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Fri Oct 13 2017 Return: Wed Oct 18 2017 Trip spans 6 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Sat Oct 14 2017 Return: Wed Oct 18 2017 Trip spans 5 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Thu Oct 12 2017 Return: Tue Oct 24 2017 Trip spans 13 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Fri Oct 13 2017 Return: Tue Oct 24 2017 Trip spans 12 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Sat Oct 14 2017 Return: Tue Oct 24 2017 Trip spans 11 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Wed Oct 18 2017 Return: Fri Oct 20 2017 Trip spans 3 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Mon Oct 23 2017 Return: Wed Nov 1 2017 Trip spans 10 days
United
United
SEA
ONT
4h 24m
1 stop
ONT
SEA
4h 38m
1 stop
Depart: Sat Oct 14 2017 Return: Wed Oct 18 2017 Trip spans 5 days
Alaska Airlines
Alaska Airlines
SEA
ONT
2h 27m
nonstop
ONT
SEA
2h 36m
nonstop
Depart: Wed Oct 25 2017 Return: Wed Nov 1 2017 Trip spans 8 days
United
United
SEA
ONT
4h 24m
1 stop
ONT
SEA
4h 38m
1 stop
Depart: Tue Oct 17 2017 Return: Wed Oct 25 2017 Trip spans 9 days
Alaska Airlines
Alaska Airlines
SEA
ONT
2h 27m
nonstop
ONT
SEA
2h 33m
nonstop
Depart: Thu Oct 12 2017 Return: Tue Oct 17 2017 Trip spans 6 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
nonstop
Depart: Tue Oct 31 2017 Return: Wed Nov 8 2017 Trip spans 9 days
United
United
SEA
ONT
5h 16m
1 stop
ONT
SEA
4h 38m
1 stop
Depart: Wed Oct 18 2017 Return: Wed Oct 25 2017 Trip spans 8 days
Alaska Airlines
Alaska Airlines
SEA
ONT
2h 27m
nonstop
ONT
SEA
2h 33m
nonstop
Depart: Wed Nov 1 2017 Return: Tue Nov 14 2017 Trip spans 14 days
United
United
SEA
ONT
4h 42m
1 stop
ONT
SEA
4h 38m
1 stop
Depart: Sat Oct 21 2017 Return: Wed Oct 25 2017 Trip spans 5 days
Frontier
Frontier
DEN
ONT
2h 24m
nonstop
ONT
DEN
2h 19m
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.

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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,
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Airports
Origin

Portland
$134
Seattle
$144
Denver
$77
Destination

Ontario
$77
Airlines Airline reviews

5 travelers who booked a flight from Denver to Ontario rated their chosen airlines with an average of 9.7.

Overall
10.0
Boarding
10.0
Crew
10.0
Comfort
9.6
Food
9.2
Entertainment
9.2