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Ontario

$99+ 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 11/4. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ONT
Jun 25 — Jul 21
Khamis 6/25
Khamis 7/2
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 Mei 26, 2026.

This CheapOair deal was found by Cheapflights users on 5/23. 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.
Jumaat 7/38:12 pm
SEA
-
ONT
1 stop23h 39m
Frontier
Ahad 7/54:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/23$183
This CheapOair deal was found by Cheapflights users on 5/23. 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.
Ahad 6/288:12 pm
SEA
-
ONT
1 stop23h 39m
Frontier
Selasa 6/304:03 pm
ONT
-
SEA
Nonstop2h 54m
Frontier
Deal found 5/23$188
This CheapOair deal was found by Cheapflights users on 5/26. 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.
Selasa 6/1611:53 am
SEA
-
ONT
Nonstop2h 46m
Frontier
Rabu 6/171:33 pm
ONT
-
SEA
1 stop21h 02m
Frontier
Deal found 5/26$189
This Kiwi.com deal was found by Cheapflights users on 5/24. 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.
Rabu 6/2411:53 am
SEA
-
ONT
Nonstop2h 46m
Frontier
Rabu 7/11:33 pm
ONT
-
SEA
1 stop21h 02m
Frontier
Deal found 5/24$197
This Kiwi.com deal was found by Cheapflights users on 5/25. 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.
Selasa 7/148:13 pm
SEA
-
ONT
1 stop11h 50m
Frontier
Isnin 7/204:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/25$199
This Super.com deal was found by Cheapflights users on 5/25. 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.
Jumaat 7/311:53 am
SEA
-
ONT
Nonstop2h 46m
Frontier
Isnin 7/64:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/25$206
This Super.com deal was found by Cheapflights users on 5/24. 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.
Khamis 7/211:53 am
SEA
-
ONT
Nonstop2h 46m
Frontier
Isnin 7/64:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/24$207
This Booking.com deal was found by Cheapflights users on 5/26. 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.
Khamis 7/2311:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Rabu 7/294:09 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/26$209
This Booking.com deal was found by Cheapflights users on 5/25. 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.
Khamis 7/911:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Jumaat 7/174:49 pm
ONT
-
SEA
Nonstop2h 49m
Frontier
Deal found 5/25$210
This Kiwi.com deal was found by Cheapflights users on 5/23. 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.
Selasa 7/1411:54 am
SEA
-
ONT
Nonstop2h 51m
Frontier
Selasa 7/213:40 pm
ONT
-
SEA
1 stop18h 59m
Frontier
Deal found 5/23$211
This Southwest deal was found by Cheapflights users on 5/22. 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.
Rabu 9/165:50 am
PDX
-
ONT
2 stops7h 45m
Southwest
Isnin 9/211:15 pm
ONT
-
PDX
1 stop5h 10m
Southwest
Deal found 5/22$212
This Southwest deal was found by Cheapflights users on 5/22. 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.
Selasa 9/111:25 am
PDX
-
ONT
1 stop4h 35m
Southwest
Khamis 10/112:35 pm
ONT
-
PDX
1 stop6h 25m
Southwest
Deal found 5/22$222

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 Mei 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$183
(CheapOair)

One-way from

$99
(Southwest)

Popular in

December

Cheapest in

March

Average price

$237

Good round-trip deal

$182 or less

Good one-way deal

$129 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. 3% potential increase in price ($8 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 May 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 Mei 26, 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

Sabtu 7/11

10:12 am-3:38 pm

1 stop5h 26m

Ontario

Rabu 7/15

2:05 pm-4:45 pm

Nonstop2h 40m

$227

PortlandOntario

PDX - ONT

PDXONT

Portland

Selasa 8/4

5:54 pm-10:45 pm

1 stop4h 51m

Ontario

Selasa 8/11

6:20 am-11:40 am

1 stop5h 20m

$227

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sabtu 7/11

10:12 am-3:38 pm

1 stop5h 26m

Ontario

Rabu 7/22

2:05 pm-4:45 pm

Nonstop2h 40m

$227

PortlandOntario

PDX - ONT

PDXONT

Portland

Sabtu 6/20

5:45 am-12:10 pm

1 stop6h 25m

Ontario

Selasa 6/23

5:59 pm-11:54 pm

1 stop5h 55m

$243

PortlandOntario

PDX - ONT

PDXONT

Portland

Ahad 9/6

5:45 am-12:05 pm

1 stop6h 20m

Ontario

Rabu 9/9

11:55 am-4:33 pm

1 stop4h 38m

$243

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Jumaat 8/21

8:43 pm-11:24 pm

Nonstop2h 41m

Ontario

Isnin 8/24

7:12 am-12:50 pm

1 stop5h 38m

$247

PortlandOntario

PDX - ONT

PDXONT

Portland

Sabtu 8/15

3:43 pm-8:01 pm

1 stop4h 18m

Ontario

Ahad 8/23

6:00 am-10:11 am

1 stop4h 11m

$259

PortlandOntario

PDX - ONT

PDXONT

Portland

Jumaat 6/19

5:20 pm-9:30 pm

1 stop4h 10m

Ontario

Jumaat 6/26

8:45 pm-1:20 am

1 stop4h 35m

$259

PortlandOntario

PDX - ONT

PDXONT

Portland

Jumaat 7/10

5:50 pm-10:43 pm

1 stop4h 53m

Ontario

Isnin 7/27

5:10 pm-11:44 pm

1 stop6h 34m

$259

PortlandOntario

PDX - ONT

PDXONT

Portland

Isnin 8/31

5:45 am-12:05 pm

1 stop6h 20m

Ontario

Khamis 9/3

9:43 am-4:03 pm

1 stop6h 20m

$259

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/25

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, November is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $48). Flying from State of Washington to Ontario in July is currently the most expensive (average of $123). 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 Mei 26, 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 32% 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 Mei 26, 2026.

The most flights from USWA to ONT are scheduled on a Sunday (19 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (11 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 59 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 May 23, 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. Friday 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 48 times in the past calendar month.

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

    Airlines like Alaska Airlines, Delta, and United Airlines fly from State of Washington to Ontario in about 4h 18m. The time it takes to get you to your destination can typically vary by up to 1h 08m. The distance from State of Washington to Ontario is about 839 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 $81 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 cheapest flights from State of Washington to Ontario?

    The cheapest flight price from State of Washington to Ontario is $74. On average you can expect to pay $304. The most popular route, (Seattle/Tacoma Intl - Ontario), can usually be booked for $200.

  • 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, November is the cheapest month in which you can book a flight from State of Washington to Ontario (average of $48). Flying from State of Washington to Ontario in July is currently the most expensive (average of $123). 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 Mei 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$78Average$195FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$98Average$302FlexibilityNo cancel feeOn-time85%
DeltaCheapest$110Average$296FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$129Average$337FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$130Average$303FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$158Average$358FlexibilityNo cancel feeOn-time69%

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