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Ontario

$110+ Cheap flights from Washington, D.C. (WAS) 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 8/4. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — ONT
Jul 9 — Jul 161
Thu 7/9
Thu 7/16
1 adult, Economy
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Cheap flight deals from Washington, D.C. to Ontario

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

This Frontier deal was found by Cheapflights users on 6/8. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/45:36 pm
BWI
-
ONT
1 stop16h 46m
Frontier
Sat 7/119:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/8$241
This Expedia deal was found by Cheapflights users on 6/7. 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.
Thu 7/212:21 pm
BWI
-
ONT
1 stop7h 27m
Frontier
Sat 7/119:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/7$242
This Frontier deal was found by Cheapflights users on 6/6. 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 7/274:44 pm
BWI
-
ONT
1 stop17h 48m
Frontier
Wed 8/59:36 am
ONT
-
BWI
1 stop8h 03m
Frontier
Deal found 6/6$243
This Booking.com deal was found by Cheapflights users on 6/9. 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.
Sat 7/45:36 pm
BWI
-
ONT
1 stop16h 46m
Frontier
Thu 7/99:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/9$244
This CheapOair deal was found by Cheapflights users on 6/8. 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 8/114:44 pm
BWI
-
ONT
1 stop17h 48m
Frontier
Thu 8/139:36 am
ONT
-
BWI
1 stop8h 03m
Frontier
Deal found 6/8$250
This Flightnetwork deal was found by Cheapflights users on 6/4. 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 Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/35:32 pm
BWI
-
ONT
1 stop27h 20m
Frontier
Sat 7/119:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/4$251
This CheapOair deal was found by Cheapflights users on 6/7. 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 8/215:19 pm
BWI
-
ONT
1 stop27h 33m
Frontier
Mon 8/315:43 pm
ONT
-
BWI
1 stop23h 54m
Frontier
Deal found 6/7$252
This Booking.com deal was found by Cheapflights users on 6/8. 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.
Sat 8/84:44 pm
BWI
-
ONT
1 stop17h 48m
Frontier
Sat 8/159:36 am
ONT
-
BWI
1 stop8h 03m
Frontier
Deal found 6/8$254
This CheapOair deal was found by Cheapflights users on 6/4. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/215:19 pm
BWI
-
ONT
1 stop27h 33m
Frontier
Tue 9/15:43 pm
ONT
-
BWI
1 stop23h 54m
Frontier
Deal found 6/4$262
This Booking.com deal was found by Cheapflights users on 6/4. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/224:44 pm
BWI
-
ONT
1 stop17h 48m
Frontier
Mon 7/279:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/4$264
This Booking.com deal was found by Cheapflights users on 6/8. 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 7/274:44 pm
BWI
-
ONT
1 stop17h 48m
Frontier
Tue 8/49:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/8$294
This Frontier deal was found by Cheapflights users on 6/7. 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 7/212:21 pm
BWI
-
ONT
1 stop7h 27m
Frontier
Wed 7/159:32 am
ONT
-
BWI
1 stop8h 04m
Frontier
Deal found 6/7$296

Find flight deals from Washington, D.C. to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Washington, D.C. (WAS) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 9, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$241
(Frontier)

One-way from

$110
(Southwest)

Popular in

April

Cheapest in

January

Average price

$381

Good round-trip deal

$490 or less

Good one-way deal

$232 or less
Provider with most accurate pricing for Washington, D.C. (WAS)-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. (WAS)-Ontario flights.
Search Deals
From Washington, D.C. (WAS) to Ontario
Search Deals
One-way flight from Washington, D.C. (WAS) to Ontario
Search Deals
Highest demand for flights based on searches. 14% potential increase in price ($66 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($14 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals
Price to beat on a round-trip flight from Washington, D.C. (WAS) to Ontario.
Search Deals
Price to beat on a one-way flight from Washington, D.C. (WAS) to Ontario.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington, D.C. 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 June 9, 2026.
Use the filters below to find and compare flights from Washington, D.C. to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 8/27

6:00 am-10:42 am

1 stop7h 42m

Ontario

Sun 8/30

10:00 pm-9:20 am

1 stop8h 20m

$326

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 7/1

5:42 pm-10:51 pm

1 stop8h 09m

Ontario

Sat 7/11

6:10 am-4:30 pm

1 stop7h 20m

$331

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 6/30

6:00 am-10:40 am

1 stop7h 40m

Ontario

Tue 7/14

11:59 am-12:08 am

1 stop9h 09m

$331

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Tue 8/11

2:45 pm-11:34 pm

2 stops11h 49m

Ontario

Mon 8/17

10:00 pm-9:10 am

1 stop8h 10m

$382

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Tue 9/15

11:40 am-5:35 pm

2 stops8h 55m

Ontario

Sat 9/19

8:45 am-7:15 pm

1 stop7h 30m

$394

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 7/14

6:00 am-10:38 am

1 stop7h 38m

Ontario

Tue 7/21

10:00 pm-9:26 am

1 stop8h 26m

$395

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Fri 7/3

6:00 pm-11:49 pm

1 stop8h 49m

Ontario

Fri 7/10

6:00 am-9:59 pm

1 stop12h 59m

$404

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sat 7/4

6:00 am-10:40 am

1 stop7h 40m

Ontario

Fri 7/10

1:00 pm-11:29 pm

1 stop7h 29m

$405

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 8/4

6:03 am-1:09 pm

1 stop10h 06m

Ontario

Sat 8/29

3:07 pm-5:40 am

1 stop11h 33m

$421

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 8/5

6:03 am-1:09 pm

1 stop10h 06m

Ontario

Wed 8/26

12:00 pm-11:59 pm

1 stop8h 59m

$421

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/9

Showing 1-10 of 60 resultsSorted by cheapest first
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Compare providers for flights from Washington, D.C. to Ontario

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Washington, D.C. to Ontario in June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C.-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C.-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C.-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C.-Ontario flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C.-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Washington, D.C. to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Washington, D.C. 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, D.C. to Ontario

What is the cheapest month to book a flight from Washington, D.C. to Ontario?

Currently, September is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $100). Flying from Washington, D.C. to Ontario in April is currently the most expensive (average of $290). 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 WAS to ONT?

Find hourly flight availability from Washington, D.C. 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 June 9, 2026.

It’s typically best to fly out from Washington, D.C. to Ontario in the morning. Doing so could potentially save you 26% on the flight price compared to flying in the afternoon, which is usually more expensive.

How much does it cost to fly round-trip from Washington, D.C. to Ontario?

How far ahead should I book a flight from Washington, D.C. to Ontario?

The best time to book flights from Washington, D.C. to Ontario is 7 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated June 9, 2026.
Read through reviews of airlines operating flights from Washington, D.C. to Ontario, such as Southwest,Delta, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!
Southwest
7.9
Good
4,240 reviews
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!
Delta
7.9
Good
8,394 reviews
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!
United Airlines
7.4
Good
9,796 reviews
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!
American Airlines
7.1
Good
11,640 reviews
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!
Frontier
5.6
Fair
2,902 reviews
Southwest
7.9
Good
4,240 reviews

Boarding

8.1

Crew

8.6

Comfort

8.0

Overall

7.9

Food

7.0

Entertainment

7.5

Reviews

1 / 20
10.0
Excellent

Walter,May 2026

LAS - BUR

Short but excellent flight. Everyone was friendly and professional it was a great flight!

Related info for your journey

Find useful and relevant information for your journey from Washington, D.C. 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, D.C.?

    Located just 3.1 mi from the city center, Ontario is the airport most travelers will use when flying to Ontario from Washington, D.C.. Booking flights from Washington, D.C. to Ontario (ONT) should be relatively easy as there are 0 daily inbound flights from Washington, D.C. from 5 different airlines.

  • How long is the flight from Washington, D.C. to Ontario?

    For as low as $326, Frontier can have you in Ontario from Washington, D.C. in 7h 42m. Washington, D.C. and Ontario are separated by a distance of 2236 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Washington, D.C. to Ontario round-trip?

    Cheapflights users have booked flights from Washington, D.C. to Ontario round-trip from $125. Other airlines that can offer you cheap pricing are Delta, from $213, and Southwest, from $269. Users have found that Frontier is 67% cheaper than the other options available to this destination.

  • What are the cheapest airlines to fly from Washington, D.C. to Ontario one-way?

    The cheapest airlines for a one-way flight from Washington, D.C. to Ontario are Frontier ($84), United Airlines ($139), and American Airlines ($149).

  • What are the most popular routes from Washington, D.C. to Ontario?

    The most popular route from Washington, D.C. to Ontario is Washington, D.C. Dulles Intl - Ontario. You may also consider Baltimore/Washington - Ontario or Washington, D.C. Reagan-National - Ontario.

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

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

  • How can I find direct flights from Washington, D.C. to Ontario?

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

  • Can I find deals for business class flights from Washington, D.C. to Ontario?

    Yes. Cheapflights offers flight deals from Washington, D.C. 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 Washington, D.C. to Ontario?

    Currently, September is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $100). Flying from Washington, D.C. to Ontario in April is currently the most expensive (average of $290). 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.

Top 5 airlines flying from Washington, D.C. to Ontario

Discover the top 5 airlines that operate flights from Washington, D.C. 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 June 9, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$330FlexibilityNo cancel feeOn-time62%
DeltaCheapest$192Average$424FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$222Average$482FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$269Average$470FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$283Average$482FlexibilityNo cancel feeOn-time71%

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