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Ontario

$96+ 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 9/10. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ONT
Aug 19 — Aug 261
Wed 8/19
Wed 8/26
1 adult, Economy
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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 July 20, 2026.

This Frontier deal was found by Cheapflights users on 7/15. 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.
Thu 8/612:19 pm
SEA
-
ONT
Nonstop2h 55m
Frontier
Wed 8/194:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 7/15$193
This CheapOair deal was found by Cheapflights users on 7/15. 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 8/2211:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Sun 8/2311:15 am
ONT
-
SEA
1 stop23h 24m
Frontier
Deal found 7/15$194
This Booking.com deal was found by Cheapflights users on 7/14. 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.
Tue 8/187:06 pm
SEA
-
ONT
1 stop14h 58m
Frontier
Tue 8/254:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 7/14$195
This Kiwi.com deal was found by Cheapflights users on 7/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/18:53 pm
SEA
-
ONT
2 stops17h 10m
Frontier
Tue 9/84:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 7/18$196
This Frontier deal was found by Cheapflights users on 7/15. 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 10/1611:15 am
SEA
-
ONT
Nonstop2h 48m
Frontier
Mon 10/195:05 pm
ONT
-
SEA
Nonstop2h 56m
Frontier
Deal found 7/15$197
This Frontier deal was found by Cheapflights users on 7/16. 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 10/1611:15 am
SEA
-
ONT
Nonstop2h 48m
Frontier
Sun 10/255:05 pm
ONT
-
SEA
Nonstop2h 56m
Frontier
Deal found 7/16$198
This Super.com deal was found by Cheapflights users on 7/18. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/2111:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Sun 8/235:17 pm
ONT
-
SEA
Nonstop2h 45m
Frontier
Deal found 7/18$200
This Kiwi.com deal was found by Cheapflights users on 7/19. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/279:29 pm
SEA
-
ONT
1 stop10h 34m
Frontier
Mon 8/315:17 pm
ONT
-
SEA
Nonstop2h 45m
Frontier
Deal found 7/19$201
This Frontier deal was found by Cheapflights users on 7/19. 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.
Sat 8/1512:19 pm
SEA
-
ONT
Nonstop2h 55m
Frontier
Mon 8/245:17 pm
ONT
-
SEA
Nonstop2h 45m
Frontier
Deal found 7/19$202
This Frontier deal was found by Cheapflights users on 7/19. 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 8/1911:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Mon 8/246:00 am
ONT
-
SEA
1 stop6h 20m
Frontier
Deal found 7/19$203
This Frontier deal was found by Cheapflights users on 7/18. 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.
Tue 8/2511:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Mon 8/316:00 am
ONT
-
SEA
1 stop6h 20m
Frontier
Deal found 7/18$204
This Delta deal was found by Cheapflights users on 7/17. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/2710:15 am
PDX
-
ONT
1 stop5h 57m
Delta
Tue 12/81:00 pm
ONT
-
PDX
1 stop5h 17m
Delta
Deal found 7/17$273

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 July 20, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$193
(Frontier)

One-way from

$96
(WAYA)

Popular in

July

Cheapest in

March

Average price

$296

Good round-trip deal

$238 or less

Good one-way deal

$179 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. 9% potential increase in price ($26 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 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 July 20, 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

Tue 9/15

3:30 pm-8:01 pm

1 stop4h 31m

Ontario

Tue 9/22

9:01 am-2:24 pm

1 stop5h 23m

$212

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 9/12

7:50 pm-10:40 pm

Nonstop2h 50m

Ontario

Mon 9/14

6:00 pm-8:50 pm

Nonstop2h 50m

$238

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 9/10

2:29 pm-5:19 pm

Nonstop2h 50m

Ontario

Mon 9/14

6:00 pm-8:50 pm

Nonstop2h 50m

$258

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 8/27

8:22 am-11:16 am

Nonstop2h 54m

Ontario

Mon 8/31

11:56 am-2:50 pm

Nonstop2h 54m

$258

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 9/3

6:10 pm-10:10 pm

1 stop4h 00m

Ontario

Mon 9/7

6:10 am-1:25 pm

1 stop7h 15m

$272

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 8/21

6:10 pm-10:10 pm

1 stop4h 00m

Ontario

Sun 8/23

6:10 pm-12:50 am

1 stop6h 40m

$272

PortlandOntario

PDX - ONT

PDXONT

Portland

Tue 11/24

5:05 pm-11:48 pm

1 stop6h 43m

Ontario

Tue 12/1

11:55 am-7:58 pm

1 stop8h 03m

$273

PortlandOntario

PDX - ONT

PDXONT

Portland

Wed 8/26

7:15 am-9:48 am

Nonstop2h 33m

Ontario

Sun 8/30

7:12 am-9:30 am

Nonstop2h 18m

$277

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Thu 9/10

3:25 pm-9:45 pm

2 stops6h 20m

Ontario

Mon 9/14

10:30 am-5:35 pm

1 stop7h 05m

$282

PortlandOntario

PDX - ONT

PDXONT

Portland

Wed 8/5

6:35 am-12:40 pm

2 stops6h 05m

Ontario

Sun 8/9

5:35 pm-10:55 pm

1 stop5h 20m

$282

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/15

Showing 1-10 of 60 resultsSorted by cheapest first
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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, October is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $203). Flying from State of Washington to Ontario in February is currently the most expensive (average of $375). 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 July 20, 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 22% on your trip compared to booking a flight in the afternoon.

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 July 20, 2026.

The most flights from USWA to ONT are scheduled on a Sunday (22 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (12 on average).

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

How far ahead should I book a flight from State of Washington to Ontario?

Booking 73 days in advance of your planned departure date is, on average, the best time to get cheap flights from State of Washington to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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 July 11, 2026.

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

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 39 times in the past calendar month.

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

    Airlines like United Airlines, Delta, and Frontier fly from State of Washington to Ontario in about 2h 50m. The time it takes to get you to your destination can typically vary by up to 18h 35m. 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 $55 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 SkyWest Airlines (89%), Delta (89%) and Frontier (89%).

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

    The cheapest flight price from State of Washington to Ontario is $69. On average you can expect to pay $357. The most popular route, (Seattle/Tacoma Intl - Ontario), can usually be booked for $166.

  • 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, October is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $203). Flying from State of Washington to Ontario in February is currently the most expensive (average of $375). 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

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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 July 20, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$72Average$210FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$98Average$336FlexibilityNo cancel feeOn-time85%
DeltaCheapest$110Average$322FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$130Average$326FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$137Average$363FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$158Average$363FlexibilityNo cancel feeOn-time69%

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