ONT

$96 Find Cheap Flights from Washington to Ontario - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Ontario departing on 8/18. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Flight Deals

Cheap Flights from Washington to Ontario

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Washington to Ontario

Sat, Aug 22 - Sun, Aug 23
Frontier Logo
8:53 pm - 8:03 am
SEA
-
ONT
11h 10m
1 stop
Frontier Logo
5:17 pm - 8:02 pm
ONT
-
SEA
2h 45mnonstop
$184Frontier
Wed, Jul 29 - Wed, Aug 12
Frontier Logo
12:35 pm - 11:50 pm
SEA
-
ONT
11h 15m
1 stop
Frontier Logo
4:09 pm - 6:58 pm
ONT
-
SEA
2h 49mnonstop
$185Frontier
Sat, Aug 15 - Sun, Aug 16
Frontier Logo
8:13 pm - 8:03 am
SEA
-
ONT
11h 50m
1 stop
Frontier Logo
4:49 pm - 7:38 pm
ONT
-
SEA
2h 49mnonstop
$186Frontier
Wed, Aug 26 - Sat, Aug 29
Southwest Logo
5:50 am - 1:35 pm
PDX
-
ONT
7h 45m
2 stops
Southwest Logo
10:15 am - 5:40 pm
ONT
-
PDX
7h 25m
2 stops
$257Southwest
Sun, Aug 23 - Sat, Aug 29
Multiple Airlines Logo
10:12 am - 8:03 am
GEG
-
ONT
21h 51m
1 stop
Multiple Airlines Logo
3:40 pm - 9:22 am
ONT
-
GEG
17h 42m
1 stop
$292Multiple Airlines
Sun, Aug 23 - Sat, Aug 29
Multiple Airlines Logo
10:12 am - 8:03 am
GEG
-
ONT
21h 51m
1 stop
Multiple Airlines Logo
3:40 pm - 9:22 am
ONT
-
GEG
17h 42m
1 stop
$296Multiple Airlines
Sat, Aug 1 - Sat, Aug 8
United Airlines Logo
1:35 pm - 6:33 pm
PSC
-
ONT
4h 58m
1 stop
United Airlines Logo
6:00 am - 11:27 am
ONT
-
PSC
5h 27m
1 stop
$311United Airlines
Sat, Aug 22 - Mon, Aug 24
Alaska Airlines Logo
10:36 am - 4:10 pm
GEG
-
ONT
5h 34m
1 stop
Alaska Airlines Logo
7:12 am - 11:52 am
ONT
-
GEG
4h 40m
1 stop
$319Alaska Airlines
Sat, Aug 22 - Mon, Aug 24
Alaska Airlines Logo
10:36 am - 4:10 pm
GEG
-
ONT
5h 34m
1 stop
Alaska Airlines Logo
7:12 am - 11:52 am
ONT
-
GEG
4h 40m
1 stop
$323Alaska Airlines
Tue, Sep 8 - Tue, Sep 15
Southwest Logo
5:45 am - 10:15 am
GEG
-
ONT
4h 30m
1 stop
Southwest Logo
11:10 am - 3:05 pm
ONT
-
GEG
3h 55m
1 stop
$328Southwest
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$96
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly and prices are also 1% lower on average.
Flight from Portland to Ontario

Flights from Washington to Ontario: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from Washington to Ontario 
Learn how KAYAK collects reviews and tips from users.
Verified travelerFlew with Hawaiian Airlines
SEA
-
ONT
Jun 2025
Make sure to be there on time because the bag drop off can be a little complicated and it takes quite some time to get to the gate.
Verified travelerFlew with Alaska Airlines
SEA
-
ONT
Oct 2024
SeaTac lets you make an appointment to get through security. SpotSaver. No cost. Online.

FAQs for booking flights from Washington to Ontario

  • How does KAYAK find such low prices on flights from Washington to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Washington is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back to Washington with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario from Washington up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario

Ontario (ONT)