HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Washington, D.C.

$108+ Cheap flights from Ontario (ONT) to Washington, D.C. (WAS)

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 8/21. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — WAS
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to Washington, D.C. 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 Ontario to Washington, D.C. are usually found in May or August, booked 70 days in advance, depart on a Wednesday or Thursday and return on a Tuesday

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

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Washington, D.C. (WAS). 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 July 31, 2025.

Round-trip from

$252
(SmartFares)

One-way from

$108
(Trip.com)

Popular in

September

Cheapest in

May

Average price

$334

Good round-trip deal

$337 or less

Good one-way deal

$206 or less
From Ontario to Washington, D.C. (WAS)
Search Deals
One-way flight from Ontario to Washington, D.C. (WAS)
Search Deals
Highest demand for flights based on searches. 1% potential increase in price ($4 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2025
Search Deals
Price to beat on a round-trip flight from Ontario to Washington, D.C. (WAS).
Search Deals
Price to beat on a one-way flight from Ontario to Washington, D.C. (WAS).
Search Deals

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

Cheapest flights from Ontario to Washington, D.C.
Explore the most affordable flight options available from Ontario to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This SmartFares deal was found by Cheapflights users on 7/29. 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 SmartFares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/2212:59 amONT - DCA
1 stop8h 12mFrontier
Sat 8/306:00 pmDCA - ONT
1 stop8h 50mFrontier
Deal found 7/29$252
This Mytrip deal was found by Cheapflights users on 7/29. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/55:15 pmONT - IAD
1 stop10h 19mFrontier
Tue 8/196:14 amIAD - ONT
1 stop13h 04mFrontier
Deal found 7/29$257
This Frontier deal was found by Cheapflights users on 7/31. 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 8/812:59 amONT - BWI
1 stop12h 32mFrontier
Sat 8/165:26 pmBWI - ONT
1 stop9h 24mFrontier
Deal found 7/31$258
This Delta deal was found by Cheapflights users on 7/30. 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 8/3011:45 amONT - IAD
1 stop8h 36mDelta
Sat 9/612:39 pmIAD - ONT
1 stop9h 32mDelta
Deal found 7/30$276
This Delta deal was found by Cheapflights users on 7/29. 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 8/237:05 amONT - DCA
1 stop7h 15mDelta
Sat 8/306:00 amDCA - ONT
1 stop7h 20mDelta
Deal found 7/29$277
This American Airlines deal was found by Cheapflights users on 7/31. 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.
Thu 8/2112:22 pmONT - IAD
2 stops8h 37mAmerican Airlines
Mon 8/2511:51 amIAD - ONT
1 stop9h 33mAmerican Airlines
Deal found 7/31$284
This American Airlines deal was found by Cheapflights users on 7/31. 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.
Thu 8/2112:22 pmONT - DCA
2 stops8h 37mAmerican Airlines
Mon 8/253:25 pmDCA - ONT
2 stops9h 14mAmerican Airlines
Deal found 7/31$289
This Alaska Airlines deal was found by Cheapflights users on 7/29. 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 10/296:00 amONT - DCA
1 stop12h 59mAlaska Airlines
Mon 11/35:53 pmDCA - ONT
1 stop9h 03mAlaska Airlines
Deal found 7/29$298
This Alaska Airlines deal was found by Cheapflights users on 7/31. 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 8/2711:39 amONT - IAD
1 stop9h 41mAlaska Airlines
Wed 9/37:00 amIAD - ONT
1 stop10h 12mAlaska Airlines
Deal found 7/31$298
This United Airlines deal was found by Cheapflights users on 7/28. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/256:04 amONT - DCA
1 stop9h 37mUnited Airlines
Mon 9/17:00 amDCA - ONT
1 stop8h 13mUnited Airlines
Deal found 7/28$319
This Southwest deal was found by Cheapflights users on 7/30. 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 8/2710:55 amONT - BWI
Nonstop4h 55mSouthwest
Wed 9/32:20 pmBWI - ONT
1 stop7h 05mSouthwest
Deal found 7/30$322
This Delta deal was found by Cheapflights users on 7/30. 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 8/307:05 amONT - BWI
1 stop7h 15mDelta
Sat 9/65:40 amBWI - ONT
1 stop7h 55mDelta
Deal found 7/30$323

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Washington, D.C. 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 31, 2025.
Use the filters below to find and compare flights from Ontario to Washington, D.C. that are best for you.

Fly from

Ontario

Fly to

Washington, D.C.

Route

Depart

Return

Price

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Fri 8/22

12:59 am-12:11 pm

1 stop8h 12m

Washington, D.C. Reagan-National

Sat 8/30

6:00 pm-11:50 pm

1 stop8h 50m

$252

OntarioBaltimore

ONT - BWI

ONTBWI

Ontario

Fri 8/8

12:59 am-4:31 pm

1 stop12h 32m

Baltimore/Washington

Sat 8/16

5:26 pm-11:50 pm

1 stop9h 24m

$258

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 8/12

5:15 pm-6:34 am

1 stop10h 19m

Washington, D.C. Dulles Intl

Sat 8/16

12:27 pm-7:14 pm

1 stop9h 47m

$258

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 8/30

11:45 am-11:21 pm

1 stop8h 36m

Washington, D.C. Dulles Intl

Sat 9/6

12:39 pm-7:11 pm

1 stop9h 32m

$276

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Sat 8/23

7:05 am-5:20 pm

1 stop7h 15m

Washington, D.C. Reagan-National

Sat 8/30

6:00 am-10:20 am

1 stop7h 20m

$277

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 8/21

12:22 pm-11:59 pm

2 stops8h 37m

Washington, D.C. Dulles Intl

Mon 8/25

11:51 am-6:24 pm

1 stop9h 33m

$284

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Thu 8/21

12:22 pm-11:59 pm

2 stops8h 37m

Washington, D.C. Reagan-National

Mon 8/25

3:25 pm-9:39 pm

2 stops9h 14m

$289

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Wed 10/29

6:00 am-9:59 pm

1 stop12h 59m

Washington, D.C. Reagan-National

Mon 11/3

5:53 pm-11:56 pm

1 stop9h 03m

$298

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 8/27

11:39 am-12:20 am

1 stop9h 41m

Washington, D.C. Dulles Intl

Wed 9/3

7:00 am-2:12 pm

1 stop10h 12m

$298

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Mon 8/25

6:04 am-6:41 pm

1 stop9h 37m

Washington, D.C. Reagan-National

Mon 9/1

7:00 am-12:13 pm

1 stop8h 13m

$319

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Showing 1-10 of 39 results
1
2
3
4

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

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

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Washington, D.C.. Price data was last updated on July 25, 2025.

The price you pay for your flight from Ontario to Washington, D.C. may vary depending on when you book. For the best chance of a lower fare, look to book 25 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, August is the cheapest month in which you can book a flight from Ontario to Washington, D.C. (average of $241). Flying from Ontario to Washington, D.C. in March 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 ONT to WAS?

Find hourly flight availability from Ontario to Washington, D.C.. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

It’s typically best to fly out from Ontario to Washington, D.C. in the afternoon. Doing so could potentially save you 32% on the flight price compared to flying at noon, which is usually more expensive.

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

Use this chart to determine the cheapest time to fly round-trip from Ontario to Washington, D.C.. Price data was last updated on July 27, 2025.

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

What’s the top layover airport for flights from Ontario to Washington, D.C.?

Share of 1-stop round-trip flights from Ontario to Washington, D.C. chosen by Cheapflights users in the past 12 months, using the same layover each way.

Denver (DEN) – chosen by Cheapflights users on 96% of 1-stop itineraries from Ontario to Washington, D.C. on Cheapflights.

What’s the cheapest layover airport for flights from Ontario to Washington, D.C.?

Average round-trip fare for 1-stop flights from Ontario to Washington, D.C., chosen by Cheapflights users in the past 12 months, with the same layover each way.

Denver (DEN) is the most affordable 1-stop option, with an average round-trip price of $280.

What’s the fastest layover option from Ontario to Washington, D.C.?

Shortest average travel time for 1-stop one-way flights from Ontario to Washington, D.C., based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Denver (DEN) have the shortest average one-way travel time for 1-stop routes: 7h 16m.

Which airport typically offers the quickest layover for flights from Ontario to Washington, D.C.?

Average layover duration for 1-stop one-way flights from Ontario to Washington, D.C., chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Denver (DEN) offer the fastest connection on this route, with an average layover time of 1h 26m.

Reviews of airlines servicing Washington, D.C.

Get insights into the airlines that provide service to Washington, D.C.. 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 Washington, D.C.. Reviews last updated July 31, 2025.
Read through reviews of airlines operating flights from Ontario to Washington, D.C., such as Alaska Airlines, Southwest, and Delta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,246 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,981 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.8
Good
2,611 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,900 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Overall

8.0

Crew

8.5

Boarding

8.1

Entertainment

7.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

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

    If you book a flight to Washington, D.C. from Ontario, you will be flying from Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario. There are 0 flights from Ontario to Washington, D.C. per day from 6 different airlines.

  • How popular is this Ontario to Washington, D.C. flight route?

    Flights from Ontario to Washington, D.C. have been viewed 4 times in the past calendar month.

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

    Cheapflights users have booked flights from Ontario to Washington, D.C. round-trip from $252. Other airlines that can offer you cheap pricing are Delta, from $276, and United Airlines, from $279. Users have found that Frontier is 26% cheaper than the other options available to this destination.

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

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $108. Users have also found prices from $136 and $140 on Hawaiian Airlines and American Airlines, respectively.

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

    When deciding which route to take from Ontario to Washington, D.C. consider Ontario - Washington, D.C. Dulles Intl, Ontario - Washington, D.C. Reagan-National or Ontario - Baltimore/Washington as they are the most popular.

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

    While on average a flight from Ontario to Washington, D.C. is generally $353, our data shows the cheapest flight currently is $102. When looking at the most popular route, (Ontario - Washington, D.C. Dulles Intl), you can expect to pay $258 for that flight.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from Ontario to Washington, D.C. (average of $241). Flying from Ontario to Washington, D.C. in March 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

Traveling to a place near Washington, D.C.?

Book flights to Washington, D.C. if you plan to visit one of these locations
Woodbridge
Arlington
Alexandria
Tysons
Silver Spring
Fredericksburg
Gaithersburg
Towson
Linthicum Heights
Easton
Fairfax
Manassas
Falls Church
Waldorf
Laurel
Rockville
Oxon Hill
National Harbor
Dundalk
Bowie

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 Ontario to Washington, D.C.

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

Top 6 airlines flying from Ontario to Washington, D.C.

Discover the top 6 airlines that operate flights from Ontario to Washington, D.C.. 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 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$98Average$212FlexibilityNo cancel feeOn-time65%
FrontierCheapest$147Average$271FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$258Average$465FlexibilityNo cancel feeOn-time63%
DeltaCheapest$286Average$417FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$286Average$491FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$298Average$467FlexibilityNo cancel feeOn-time69%

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.