ONT

$64 Find Cheap Flights from Washington to Ontario

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 5/16. 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

KAYAK searches hundreds of travel sites at once for deals on flights to Ontario

Travelers love KAYAK
41.299.237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$154
Overall average: $228
Frontier
Wed 4/22Thu 4/30
SEA - ONT • 1 stop
Cheapest non-stop
$157
Typical prices: $109-$264
Alaska Airlines
Wed 3/4Sat 3/7
SEA - ONT • Non-stop
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Ontario!
Flight Deals
Useful Info
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

Wed, Apr 22 - Thu, Apr 30
Frontier Logo
6:57 pm - 7:31 am
SEA
-
ONT
12h 34m
1 stop
Frontier Logo
11:44 am - 8:20 pm
ONT
-
SEA
8h 36m
1 stop
$154Frontier
Thu, Feb 26 - Wed, Mar 4
Frontier Logo
1:16 pm - 11:59 pm
SEA
-
ONT
10h 43m
1 stop
Frontier Logo
7:17 pm - 8:08 pm
ONT
-
SEA
24h 51m
1 stop
$156Frontier
Wed, Mar 4 - Sat, Mar 7
Alaska Airlines Logo
8:05 pm - 10:44 pm
SEA
-
ONT
2h 39mnonstop
Alaska Airlines Logo
12:02 pm - 2:52 pm
ONT
-
SEA
2h 50mnonstop
$157Alaska Airlines
Wed, Apr 29 - Tue, May 5
Alaska Airlines Logo
9:30 pm - 11:48 pm
PDX
-
ONT
2h 18mnonstop
Alaska Airlines Logo
7:00 am - 9:24 am
ONT
-
PDX
2h 24mnonstop
$157Alaska Airlines
Thu, May 14 - Fri, May 15
Multiple Airlines Logo
9:22 pm - 11:58 pm
SEA
-
ONT
2h 36mnonstop
Multiple Airlines Logo
12:59 am - 9:27 am
ONT
-
SEA
8h 28m
1 stop
$159Multiple Airlines
Thu, Apr 16 - Sun, Apr 19
Frontier Logo
9:35 pm - 8:04 am
SEA
-
ONT
10h 29m
1 stop
Frontier Logo
12:59 am - 9:27 am
ONT
-
SEA
8h 28m
1 stop
$160Frontier
Sat, Mar 14 - Mon, Mar 16
Hawaiian Airlines Logo
8:56 pm - 11:32 pm
SEA
-
ONT
2h 36mnonstop
Hawaiian Airlines Logo
6:14 am - 9:09 am
ONT
-
SEA
2h 55mnonstop
$161Hawaiian Airlines
Wed, Mar 11 - Sun, Mar 15
United Airlines Logo
1:39 pm - 5:41 pm
PDX
-
ONT
4h 02m
1 stop
United Airlines Logo
6:15 am - 12:33 pm
ONT
-
PDX
6h 18m
1 stop
$162United Airlines
Wed, Mar 11 - Mon, Mar 16
Hawaiian Airlines Logo
8:05 pm - 10:44 pm
SEA
-
ONT
2h 39mnonstop
Hawaiian Airlines Logo
6:14 am - 9:09 am
ONT
-
SEA
2h 55mnonstop
$163Hawaiian Airlines
Sun, Apr 26 - Wed, Apr 29
Multiple Airlines Logo
6:00 am - 8:04 am
BLI
-
ONT
26h 04m
1 stop
Multiple Airlines Logo
7:29 pm - 11:35 pm
ONT
-
BLI
28h 06m
1 stop
$188Multiple Airlines
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$64
Best time to beat the crowds with an average 1% drop in price.
Most popular time to fly with an average 2% increase in price.
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)