HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$75+ Cheap flights from Washington to Ontario (ONT)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ONT
May 9 — May 161
Sat 5/9
Sat 5/16
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Washington to Ontario with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Washington to Ontario

Cheapest flights from Washington to Ontario
Explore the most affordable flight options available from Washington to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 9, 2026.

This Frontier deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/274:20 pm
SEA
-
ONT
1 stop7h 35m
Frontier
Wed 4/2912:59 am
ONT
-
SEA
1 stop8h 28m
Frontier
Deal found 4/6$140
This Booking.com deal was found by Cheapflights users on 4/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/310:25 pm
SEA
-
ONT
1 stop21h 39m
Frontier
Wed 5/64:39 pm
ONT
-
SEA
1 stop17h 43m
Frontier
Deal found 4/8$141
This CheapOair deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/237:50 pm
SEA
-
ONT
1 stop14h 15m
Frontier
Sun 5/244:04 pm
ONT
-
SEA
Nonstop3h 01m
Frontier
Deal found 4/6$145
This Frontier deal was found by Cheapflights users on 4/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/2211:51 am
SEA
-
ONT
Nonstop2h 44m
Frontier
Sun 5/244:04 pm
ONT
-
SEA
Nonstop3h 01m
Frontier
Deal found 4/5$148
This Frontier deal was found by Cheapflights users on 4/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 6/711:51 am
SEA
-
ONT
Nonstop2h 44m
Frontier
Mon 6/84:04 pm
ONT
-
SEA
Nonstop3h 01m
Frontier
Deal found 4/4$149
This CheapOair deal was found by Cheapflights users on 4/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/911:53 am
SEA
-
ONT
Nonstop2h 46m
Frontier
Tue 6/163:34 pm
ONT
-
SEA
1 stop19h 01m
Frontier
Deal found 4/8$150
This CheapOair deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/812:33 pm
GEG
-
ONT
1 stop21h 32m
Frontier
Mon 5/116:00 am
ONT
-
GEG
1 stop5h 38m
Frontier
Deal found 4/6$151
This Booking.com deal was found by Cheapflights users on 4/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1111:37 am
SEA
-
ONT
1 stop7h 55m
Frontier
Wed 5/134:39 pm
ONT
-
SEA
1 stop17h 43m
Frontier
Deal found 4/8$152
This Priceline deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/2111:51 am
SEA
-
ONT
Nonstop2h 44m
Frontier
Thu 5/214:04 pm
ONT
-
SEA
Nonstop3h 01m
Frontier
Deal found 4/6$153
This CheapOair deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/511:51 am
SEA
-
ONT
Nonstop2h 44m
Frontier
Mon 6/83:30 pm
ONT
-
SEA
1 stop19h 05m
Frontier
Deal found 4/6$154
This CheapOair deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/611:51 am
SEA
-
ONT
Nonstop2h 44m
Frontier
Sun 6/73:30 pm
ONT
-
SEA
1 stop19h 06m
Frontier
Deal found 4/6$155
This Frontier deal was found by Cheapflights users on 4/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/2212:38 pm
PDX
-
ONT
1 stop11h 17m
Frontier
Tue 4/2812:59 am
ONT
-
PDX
1 stop10h 53m
Frontier
Deal found 4/6$160

Find flight deals from Washington to Ontario

Keep the following information in mind while searching for Washington to Ontario flight deals. Data was last updated April 9, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$140
(Frontier)

One-way from

$75
(Super.com)

Popular in

December

Cheapest in

May

Average price

$249

Good round-trip deal

$238 or less

Good one-way deal

$135 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Los Angeles flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Los Angeles flights.
Search Deals
From Washington to Ontario
Search Deals
One-way flight from Washington to Ontario
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($13 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($3 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
Search Deals
Price to beat on a round-trip flight from Washington to Ontario.
Search Deals
Price to beat on a one-way flight from Washington to Ontario.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington to Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 9, 2026.
Use the filters below to find and compare flights from Washington to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 5/6

7:05 am-9:45 am

Nonstop2h 40m

Ontario

Wed 5/13

4:03 pm-6:52 pm

Nonstop2h 49m

$177

SpokaneOntario

GEG - ONT

GEGONT

Spokane

Mon 6/1

12:33 pm-11:49 pm

1 stop11h 16m

Ontario

Mon 6/8

6:00 am-11:38 am

1 stop5h 38m

$201

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 5/9

7:05 am-9:45 am

Nonstop2h 40m

Ontario

Mon 5/11

6:00 am-8:50 am

Nonstop2h 50m

$207

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sun 5/17

5:00 am-9:05 am

1 stop4h 05m

Ontario

Tue 5/19

3:30 pm-9:00 pm

1 stop5h 30m

$217

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 5/5

7:05 am-9:45 am

Nonstop2h 40m

Ontario

Wed 5/6

3:24 pm-6:15 pm

Nonstop2h 51m

$217

PortlandOntario

PDX - ONT

PDXONT

Portland

Thu 4/30

9:30 pm-11:48 pm

Nonstop2h 18m

Ontario

Sun 5/3

7:00 am-9:24 am

Nonstop2h 24m

$217

PortlandOntario

PDX - ONT

PDXONT

Portland

Tue 5/5

8:45 am-2:32 pm

1 stop5h 47m

Ontario

Sat 5/9

3:26 pm-8:17 pm

1 stop4h 51m

$237

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 5/20

4:10 pm-6:47 pm

Nonstop2h 37m

Ontario

Tue 5/26

7:48 pm-6:52 pm

1 stop23h 04m

$240

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 4/29

2:30 pm-5:15 pm

Nonstop2h 45m

Ontario

Thu 4/30

11:53 am-2:57 pm

Nonstop3h 04m

$247

PortlandOntario

PDX - ONT

PDXONT

Portland

Thu 4/30

9:30 pm-11:48 pm

Nonstop2h 18m

Ontario

Sat 5/9

3:26 pm-8:17 pm

1 stop4h 51m

$247

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/5

Showing 1-10 of 60 resultsSorted by cheapest first
1
2
3
...
6

Best time to book a flight from Washington to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Washington with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington to Ontario

What is the cheapest month to book a flight from State of Washington to Ontario?

Currently, August is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $44). Flying from State of Washington to Ontario in November is currently the most expensive (average of $107). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from WA to ONT?

Find hourly flight availability from Washington to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 9, 2026.

A simple way to save on the total cost of your ticket is to fly from State of Washington to Ontario at noon. If you’re flexible enough to do this you can expect to save up to 26% on your trip compared to booking a flight in the afternoon.

What is the cheapest day to fly from State of Washington to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Washington to Ontario. Price data was last updated on April 4, 2026.

Travelers seeking maximum savings on their State of Washington to Ontario flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Friday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from State of Washington to Ontario

Explore weekly flight availability from Washington to Ontario. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated April 9, 2026.

The most flights from USWA to ONT are scheduled on a Monday (15 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (10 on average).

How much does it cost to fly round-trip from State of Washington to Ontario?

Related info for your journey

Find useful and relevant information for your journey from Washington to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Ontario from Washington?

    Most people fly into Ontario (ONT) if they book a flight to Ontario from Washington. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

  • How popular is this State of Washington to Ontario flight route?

    Flights from Washington to Ontario have been viewed 50 times in the past calendar month.

  • How long is the flight from State of Washington to Ontario?

    Airlines like Alaska Airlines, Frontier, and Southwest fly from State of Washington to Ontario in about 2h 40m. The time it takes to get you to your destination can typically vary by up to 8h 36m. The distance from State of Washington to Ontario is about 956 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from State of Washington to Ontario one-way?

    One-way options have recently been found by users for as low as $53 on Frontier. Other airlines that offer cheap prices include Southwest from $62 and Delta from $79 one-way.

  • What are the most popular routes from State of Washington to Ontario?

    While some choose either Portland - Ontario or Spokane - Ontario, Seattle/Tacoma Intl - Ontario is the most popular route from State of Washington to Ontario.

  • What are the most reliable airlines from State of Washington to Ontario?

    The top 3 most reliable airlines when flying from State of Washington to Ontario are KLM (94%), Alaska Airlines (89%) and Qatar Airways (87%).

  • What are the cheapest flights from State of Washington to Ontario?

    The cheapest flight price from State of Washington to Ontario is $79. On average you can expect to pay $269. The most popular route, (Seattle/Tacoma Intl - Ontario), can usually be booked for $89.

  • Can I find deals for flights from Washington to Ontario that include hotel bookings?

    Yes. In addition to deals on Washington to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Washington to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Washington to Ontario.

  • Can I find deals for business class flights from Washington to Ontario?

    Yes. Cheapflights offers flight deals from Washington to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from State of Washington to Ontario?

    Currently, August is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $44). Flying from State of Washington to Ontario in November is currently the most expensive (average of $107). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Washington to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
Newark to San Francisco flights
John F Kennedy Intl to San Francisco flights
LaGuardia to San Francisco flights
Seattle to Las Vegas flights
John F Kennedy Intl to Las Vegas flights
Seattle to Los Angeles flights
O'Hare Intl to Las Vegas flights
John F Kennedy Intl to Los Angeles flights
Newark to Los Angeles flights
San Francisco to Las Vegas flights
Newark to Las Vegas flights
San Francisco to Los Angeles flights
Dallas/Fort Worth to Los Angeles flights
Dallas/Fort Worth to Las Vegas flights
Dulles Intl to Las Vegas flights
LaGuardia to Los Angeles flights
Denver to Las Vegas flights
LaGuardia to Las Vegas flights
Los Angeles to San Francisco flights
San Francisco to Santa Ana flights
Atlanta to Las Vegas flights
Dallas/Fort Worth to San Francisco flights
San Francisco to Ontario flights
Seattle to San Francisco flights
Los Angeles to Las Vegas flights
Boston to Las Vegas flights
Ontario to San Francisco flights
Detroit to Las Vegas flights
Minneapolis to Las Vegas flights
Dulles Intl to Los Angeles flights
Baltimore to Los Angeles flights
Reagan-National to Los Angeles flights
Burbank to Las Vegas flights
Boston to Los Angeles flights
Reagan-National to Las Vegas flights
Baltimore to Las Vegas flights
O'Hare Intl to Los Angeles flights
Atlanta to Los Angeles flights
O'Hare Intl to San Francisco flights
Seattle to Ontario flights
Boston to San Francisco flights
San Francisco to San Diego flights
San Jose to Las Vegas flights
San Jose to Los Angeles flights
Seattle to San Diego flights
Hobby to Los Angeles flights
Portland to Las Vegas flights
Santa Ana to San Francisco flights
Hobby to Las Vegas flights
Orlando to Las Vegas flights

Top 6 airlines flying from Washington to Ontario

Discover the top 6 airlines that operate flights from Washington to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 9, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$69Average$186FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$98Average$260FlexibilityNo cancel feeOn-time85%
DeltaCheapest$105Average$283FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$113Average$300FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$129Average$327FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$158Average$353FlexibilityNo cancel feeOn-time69%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.