HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$87+ 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 4/30. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — ONT
Apr 20 — Apr 271
Sun 4/20
Sun 4/27
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Washington, D.C. 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.

Cheapflights Tip: The best prices from Washington, D.C. to Ontario are usually found in August or October, booked 78 days in advance, depart on a Tuesday or Saturday and return on a Wednesday

Cheap 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 April 15, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$198
(Frontier)

One-way from

$87
(Cheapflightsfares)

Popular in

June

Cheapest in

August

Average price

$348

Good round-trip deal

$471 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. 1% potential increase in price ($6 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2025
Search Deals
Price to beat on a round-trip flight from Washington, D.C. (WAS) to Ontario.
Search Deals

Find 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 April 15, 2025.

This CheapOair deal was found by Cheapflights users on 4/13. 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.
Wed 4/168:49 pmBWI - ONT
1 stop13h 40mFrontier
Thu 4/2412:59 amONT - BWI
1 stop12h 59mFrontier
Deal found 4/13$190
This FlightHub deal was found by Cheapflights users on 4/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/171:03 pmDCA - ONT
1 stop23h 19mFrontier
Wed 4/2312:10 pmONT - DCA
1 stop25h 49mFrontier
Deal found 4/14$233
This Cheapflightsfares deal was found by Cheapflights users on 4/15. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/137:45 amIAD - ONT
1 stop7h 23mFrontier
Fri 5/307:37 pmONT - IAD
1 stop7h 18mFrontier
Deal found 4/15$238
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/247:51 amBWI - ONT
1 stop9h 15mAlaska Airlines
Tue 10/74:05 pmONT - BWI
1 stop10h 40mAlaska Airlines
Deal found 4/14$277
This Expedia deal was found by Cheapflights users on 4/14. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/56:12 pmBWI - ONT
1 stop8h 47mMultiple Airlines
Fri 5/94:29 pmONT - BWI
1 stop10h 17mMultiple Airlines
Deal found 4/14$282
This Alaska Airlines deal was found by Cheapflights users on 4/15. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/146:30 amIAD - ONT
1 stop12h 02mAlaska Airlines
Tue 11/44:05 pmONT - IAD
1 stop10h 50mAlaska Airlines
Deal found 4/15$292
This American Airlines deal was found by Cheapflights users on 4/14. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/55:00 pmDCA - ONT
1 stop7h 57mAmerican Airlines
Tue 5/1310:40 pmONT - DCA
1 stop7h 48mAmerican Airlines
Deal found 4/14$327
This Delta deal was found by Cheapflights users on 4/15. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/107:30 amIAD - ONT
1 stop7h 45mDelta
Wed 5/1412:18 pmONT - IAD
1 stop8h 17mDelta
Deal found 4/15$327
This Southwest deal was found by Cheapflights users on 4/14. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/56:55 amDCA - ONT
1 stop7h 10mSouthwest
Tue 5/138:50 amONT - DCA
2 stops9h 05mSouthwest
Deal found 4/14$332
This American Airlines deal was found by Cheapflights users on 4/15. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/31:59 pmIAD - ONT
2 stops12h 44mAmerican Airlines
Mon 6/912:59 amONT - IAD
1 stop7h 01mAmerican Airlines
Deal found 4/15$332
This Delta deal was found by Cheapflights users on 4/14. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/106:00 amDCA - ONT
2 stops9h 15mDelta
Tue 5/137:05 amONT - DCA
2 stops12h 44mDelta
Deal found 4/14$337
This Southwest deal was found by Cheapflights users on 4/13. 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 7/173:20 pmBWI - ONT
Nonstop5h 20mSouthwest
Sun 7/279:20 pmONT - BWI
Nonstop4h 50mSouthwest
Deal found 4/13$345

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 April 15, 2025.
Use the filters below to find and compare flights from Washington, D.C. to Ontario that are best for you.

Fly from

Washington, D.C.

Fly to

Ontario

Route

Depart

Return

Price

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Mon 5/5

6:12 pm-11:59 pm

1 stop8h 47m

Ontario

Sun 5/11

12:59 am-5:22 pm

1 stop13h 23m

$198

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 5/21

7:45 am-12:08 pm

1 stop7h 23m

Ontario

Sat 5/31

5:15 pm-5:55 am

1 stop9h 40m

$232

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Fri 5/16

6:00 pm-11:59 pm

1 stop8h 59m

Ontario

Thu 5/22

12:59 am-12:07 pm

1 stop8h 08m

$238

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Mon 5/5

6:12 pm-11:59 pm

1 stop8h 47m

Ontario

Fri 5/9

4:29 pm-5:46 am

1 stop10h 17m

$282

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 5/13

6:30 am-3:32 pm

1 stop12h 02m

Ontario

Tue 5/20

7:20 pm-7:36 am

1 stop9h 16m

$292

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Thu 5/8

7:06 am-3:32 pm

1 stop11h 26m

Ontario

Sat 5/10

4:29 pm-5:46 am

1 stop10h 17m

$305

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Mon 5/5

5:00 pm-9:57 pm

1 stop7h 57m

Ontario

Tue 5/13

10:40 pm-9:28 am

1 stop7h 48m

$327

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 5/28

7:30 am-12:15 pm

1 stop7h 45m

Ontario

Wed 6/4

2:55 pm-5:52 am

1 stop11h 57m

$327

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Mon 5/5

6:55 am-11:05 am

1 stop7h 10m

Ontario

Fri 5/9

9:55 am-10:10 pm

2 stops9h 15m

$332

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 6/3

5:02 am-1:52 pm

2 stops11h 50m

Ontario

Mon 6/9

12:59 am-11:00 am

1 stop7h 01m

$332

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/14

Showing 1-10 of 45 results
1
2
3
...
5

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 April.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
Kiwi.comPrice 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 Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on Washington, D.C.-Ontario flight deals on Cheapflights vs. Mytrip >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 Mytrip the most. Mytrip 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

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

Use this chart to determine the optimal time to book a round-trip flight from Washington, D.C. to Ontario. Price data was last updated on April 11, 2025.

The best time to book flights from Washington, D.C. to Ontario is 77 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.

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

Currently, August is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $246). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $328). 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 April 15, 2025.

It’s typically best to fly out from Washington, D.C. to Ontario in the afternoon. Doing so could potentially save you 16% on the flight price compared to flying in the evening, which is usually more expensive.

What is the cheapest day to fly from Washington, D.C. to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Washington, D.C. to Ontario. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Washington, D.C. to Ontario flight should consider departing on Saturday evenings when fares are most often at their lowest. Friday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

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 April 15, 2025.
See what other customers who have flown with Alaska Airlines, Southwest and Delta from Washington, D.C. to Ontario have to say. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Alaska Airlines
8.0
Very good
9,876 reviews
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Southwest
8.0
Very good
4,279 reviews
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Delta
8.0
Very good
7,917 reviews
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
Hawaiian Airlines
7.9
Good
2,374 reviews
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >
United Airlines
7.4
Good
8,658 reviews
Alaska Airlines
8.0
Very good
9,876 reviews

Entertainment

7.1

Overall

8.0

Comfort

7.9

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
4.0
Okay

Anonymous,Apr 2025

LAS - STS

flight was delayed both ways even tho the weather was clear >

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.

  • 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 $198. Other airlines that can offer you cheap pricing are Alaska Airlines, from $277, and American Airlines, from $327. Users have found that Frontier is 48% 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 ($87), Alaska Airlines ($138), and Hawaiian Airlines ($163).

  • 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.

  • What are the cheapest flights from Washington, D.C. to Ontario?

    The cheapest flight price from Washington, D.C. to Ontario is $357. On average you can expect to pay $513. The most popular route, (Washington, D.C. Dulles Intl - Ontario), can usually be booked for $188.

  • 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, August is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $246). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $328). 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, D.C. to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
Dulles Intl to Las Vegas flights
Reagan-National to Los Angeles flights
Dulles Intl to Los Angeles flights
Reagan-National to Las Vegas flights
Dulles Intl to San Francisco flights
Reagan-National to San Francisco flights
Dulles Intl to San Diego flights
Reagan-National to San Diego flights
Dulles Intl to Ontario flights
Dulles Intl to Sacramento flights
Reagan-National to Santa Ana flights
Reagan-National to Ontario flights
Dulles Intl to Santa Ana flights
Dulles Intl to San Jose flights
Reagan-National to San Jose flights
Reagan-National to Sacramento flights
Dulles Intl to Palm Springs flights
Dulles Intl to Reno flights
Reagan-National to Palm Springs flights
Dulles Intl to Oakland flights
Reagan-National to Reno flights
Dulles Intl to Fresno flights
Reagan-National to Burbank flights
Dulles Intl to Burbank flights
Reagan-National to Oakland flights
Reagan-National to Fresno flights
Dulles Intl to Santa Barbara flights
Dulles Intl to Monterey flights
Reagan-National to Santa Barbara flights
Reagan-National to Monterey flights
Reagan-National to San Luis Obispo flights
Dulles Intl to Long Beach flights
Dulles Intl to Medford flights
Dulles Intl to Santa Rosa flights
Dulles Intl to San Luis Obispo flights
Reagan-National to Long Beach flights
Dulles Intl to Bakersfield flights
Reagan-National to Medford flights
Reagan-National to Santa Rosa flights
Dulles Intl to Arcata flights
Reagan-National to Bakersfield flights
Reagan-National to Arcata flights
Dulles Intl to Redding flights
Reagan-National to Tijuana flights
Reagan-National to Yuma flights
Dulles Intl to Mammoth Lakes flights
Dulles Intl to Merced flights
Reagan-National to Redding flights
Reagan-National to Mammoth Lakes flights

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 April 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$150Average$258FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$195Average$473FlexibilityNo cancel feeOn-time69%
DeltaCheapest$286Average$438FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$286Average$471FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$327Average$519FlexibilityNo cancel feeOn-time63%

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.