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$68+ 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 3/30. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ONT
Mar 22 — Mar 291
Sun 3/22
Sun 3/29
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 February 20, 2026.

This Kiwi.com deal was found by Cheapflights users on 2/20. 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 3/316:24 pm
SEA
-
ONT
2 stops21h 33m
Multiple Airlines
Mon 4/1312:59 am
ONT
-
SEA
1 stop8h 28m
Multiple Airlines
Deal found 2/20$154
This Expedia deal was found by Cheapflights users on 2/18. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/2710:11 pm
SEA
-
ONT
1 stop12h 33m
Multiple Airlines
Thu 4/307:59 pm
ONT
-
SEA
Nonstop2h 51m
Multiple Airlines
Deal found 2/18$155
This Southwest deal was found by Cheapflights users on 2/16. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/1211:10 am
SEA
-
ONT
1 stop8h 40m
Southwest
Mon 3/164:20 pm
ONT
-
SEA
1 stop7h 30m
Southwest
Deal found 2/16$156
This Delta deal was found by Cheapflights users on 2/18. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/102:30 pm
SEA
-
ONT
Nonstop2h 42m
Delta
Sun 3/156:00 am
ONT
-
SEA
Nonstop2h 55m
Delta
Deal found 2/18$157
This Alaska Airlines deal was found by Cheapflights users on 2/19. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/129:30 pm
PDX
-
ONT
Nonstop2h 22m
Alaska Airlines
Tue 3/177:00 am
ONT
-
PDX
Nonstop2h 28m
Alaska Airlines
Deal found 2/19$157
This Alaska Airlines deal was found by Cheapflights users on 2/19. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/148:56 pm
SEA
-
ONT
Nonstop2h 36m
Alaska Airlines
Sun 3/156:14 am
ONT
-
SEA
Nonstop2h 55m
Alaska Airlines
Deal found 2/19$158
This Frontier deal was found by Cheapflights users on 2/20. 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 4/167:12 pm
SEA
-
ONT
1 stop12h 19m
Frontier
Sun 4/1912:59 am
ONT
-
SEA
1 stop8h 28m
Frontier
Deal found 2/20$160
This Frontier deal was found by Cheapflights users on 2/16. 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.
Mon 4/1311:58 am
PDX
-
ONT
1 stop11h 58m
Frontier
Mon 4/2012:59 am
ONT
-
PDX
1 stop12h 03m
Frontier
Deal found 2/16$160
This Frontier deal was found by Cheapflights users on 2/19. 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.
Thu 4/2311:44 am
GEG
-
ONT
1 stop12h 11m
Frontier
Sat 4/2512:59 am
ONT
-
GEG
1 stop9h 50m
Frontier
Deal found 2/19$160
This Alaska Airlines deal was found by Cheapflights users on 2/19. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/188:26 am
SEA
-
ONT
1 stop7h 16m
Alaska Airlines
Wed 3/257:08 pm
ONT
-
SEA
Nonstop2h 49m
Alaska Airlines
Deal found 2/19$161
This Booking.com deal was found by Cheapflights users on 2/16. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/1012:42 pm
SEA
-
ONT
1 stop11h 14m
Frontier
Sun 4/126:10 pm
ONT
-
SEA
1 stop26h 09m
Frontier
Deal found 2/16$162
This Southwest deal was found by Cheapflights users on 2/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/151:10 pm
PDX
-
ONT
1 stop3h 55m
Southwest
Sat 4/185:30 am
ONT
-
PDX
2 stops7h 25m
Southwest
Deal found 2/19$162

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 February 20, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$155
(Expedia)

One-way from

$68
(Kiwi.com)

Popular in

December

Cheapest in

March

Average price

$264

Good round-trip deal

$186 or less

Good one-way deal

$169 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 ($24 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 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 February 20, 2026.
Use the filters below to find and compare flights from Washington to Ontario that are best for you.

Fly from

Washington

Fly to

Ontario

Route

Depart

Return

Price

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sun 4/19

8:25 am-11:13 am

Nonstop2h 48m

Ontario

Fri 4/24

5:55 pm-8:55 pm

Nonstop3h 00m

$157

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 3/16

5:10 pm-11:52 pm

1 stop6h 42m

Ontario

Thu 3/19

7:08 pm-9:57 pm

Nonstop2h 49m

$157

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 3/11

2:30 pm-5:12 pm

Nonstop2h 42m

Ontario

Sun 3/15

6:00 am-8:55 am

Nonstop2h 55m

$157

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 3/10

5:10 pm-11:52 pm

1 stop6h 42m

Ontario

Wed 3/11

4:02 pm-6:52 pm

Nonstop2h 50m

$157

PortlandOntario

PDX - ONT

PDXONT

Portland

Sat 4/11

5:58 pm-8:23 pm

Nonstop2h 25m

Ontario

Tue 4/21

10:59 am-1:26 pm

Nonstop2h 27m

$157

PortlandOntario

PDX - ONT

PDXONT

Portland

Tue 4/14

5:58 pm-8:23 pm

Nonstop2h 25m

Ontario

Tue 4/21

10:59 am-1:26 pm

Nonstop2h 27m

$157

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Wed 3/11

8:30 am-11:08 am

Nonstop2h 38m

Ontario

Wed 3/18

4:22 pm-8:58 pm

1 stop4h 36m

$161

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Mon 3/23

7:50 pm-10:34 pm

Nonstop2h 44m

Ontario

Thu 4/2

5:09 pm-12:03 am

1 stop6h 54m

$167

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 4/14

2:30 pm-5:15 pm

Nonstop2h 45m

Ontario

Fri 4/17

5:05 pm-11:59 pm

1 stop6h 54m

$167

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 3/14

5:30 am-12:23 pm

1 stop6h 53m

Ontario

Sun 3/15

6:00 am-8:55 am

Nonstop2h 55m

$167

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/16

Showing 1-10 of 60 results
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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, March is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $45). 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 February 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 23% 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 February 17, 2026.

Travelers seeking maximum savings on their State of Washington to Ontario flight should consider departing on Sunday 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 February 20, 2026.

The most flights from USWA to ONT are scheduled on a Thursday (15 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (9 on average).

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 49 times in the past calendar month.

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

    Airlines like Delta, Alaska Airlines, and United Airlines fly from State of Washington to Ontario in about 2h 48m. The time it takes to get you to your destination can typically vary by up to 5h 04m. 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 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 WestJet (85%), Korean Air (82%) and Virgin Atlantic (81%).

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

    The cheapest flight price from State of Washington to Ontario is $98. On average you can expect to pay $264. The most popular route, (Seattle/Tacoma Intl - Ontario), can usually be booked for $97.

  • 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, March is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $45). 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.

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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 February 20, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$64Average$177FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$97Average$245FlexibilityNo cancel feeOn-time85%
DeltaCheapest$107Average$288FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$113Average$299FlexibilityNo cancel feeOn-time63%
Alaska AirlinesCheapest$129Average$310FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$158Average$368FlexibilityNo cancel feeOn-time69%

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