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Washington, D.C.

$98+ 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 5/28. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — WAS
May 18 — May 251
Sun 5/18
Sun 5/25
1 adult, Economy
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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

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3. Compare prices and book

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Cheapflights Tip: The best prices from Ontario to Washington, D.C. are usually found in August or April, 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 May 13, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$200
(Frontier)

One-way from

$99
(Cheapflightsfares)

Popular in

September

Cheapest in

August

Average price

$333

Good round-trip deal

$379 or less

Good one-way deal

$171 or less
Provider with most accurate pricing for Ontario-Washington, D.C. (WAS) flight deals.
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Provider most trusted by Cheapflights users for Ontario-Washington, D.C. (WAS) flights.
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From Ontario to Washington, D.C. (WAS)
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One-way flight from Ontario to Washington, D.C. (WAS)
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High demand for flights, 0% potential price rise
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in May 2025
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Price to beat on a round-trip flight from Ontario to Washington, D.C. (WAS).
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Price to beat on a one-way flight from Ontario to Washington, D.C. (WAS).
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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 May 13, 2025.

This Frontier deal was found by Cheapflights users on 5/12. 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 5/245:15 pmONT - IAD
1 stop9h 40mFrontier
Sat 5/317:25 amIAD - ONT
1 stop11h 55mFrontier
Deal found 5/12$200
This Gotogate deal was found by Cheapflights users on 5/12. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/45:21 pmONT - DCA
1 stop15h 39mFrontier
Sat 6/71:00 pmDCA - ONT
1 stop23h 12mFrontier
Deal found 5/12$209
This Frontier deal was found by Cheapflights users on 5/12. 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 5/2312:59 amONT - BWI
1 stop12h 54mFrontier
Mon 6/25:20 pmBWI - ONT
1 stop9h 30mFrontier
Deal found 5/12$210
This Alaska Airlines deal was found by Cheapflights users on 5/10. 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 5/297:20 pmONT - IAD
1 stop9h 16mAlaska Airlines
Tue 6/39:00 amIAD - ONT
1 stop9h 50mAlaska Airlines
Deal found 5/10$326
This Delta deal was found by Cheapflights users on 5/12. 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 5/246:00 amONT - DCA
1 stop7h 00mDelta
Tue 6/36:59 amDCA - ONT
1 stop7h 09mDelta
Deal found 5/12$327
This Delta deal was found by Cheapflights users on 5/12. 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 5/241:10 pmONT - IAD
1 stop7h 43mDelta
Tue 6/36:00 amIAD - ONT
1 stop8h 08mDelta
Deal found 5/12$327
This American Airlines deal was found by Cheapflights users on 5/12. 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.
Wed 5/2110:51 amONT - DCA
1 stop7h 04mAmerican Airlines
Fri 5/235:00 amDCA - ONT
1 stop9h 50mAmerican Airlines
Deal found 5/12$329
This Southwest deal was found by Cheapflights users on 5/12. 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 6/269:20 pmONT - BWI
Nonstop4h 50mSouthwest
Sat 7/58:55 pmBWI - ONT
Nonstop5h 20mSouthwest
Deal found 5/12$337
This American Airlines deal was found by Cheapflights users on 5/12. 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.
Wed 6/47:25 pmONT - IAD
2 stops10h 13mAmerican Airlines
Sat 6/711:50 amIAD - ONT
2 stops12h 48mAmerican Airlines
Deal found 5/12$337
This Orbitz deal was found by Cheapflights users on 5/12. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/114:45 pmONT - BWI
1 stop10h 44mMultiple Airlines
Wed 6/185:20 pmBWI - ONT
1 stop9h 30mMultiple Airlines
Deal found 5/12$352
This Expedia deal was found by Cheapflights users on 5/10. 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 5/122:28 pmONT - IAD
1 stop13h 03mMultiple Airlines
Sun 8/247:00 amIAD - ONT
1 stop10h 09mMultiple Airlines
Deal found 5/10$354
This Delta deal was found by Cheapflights users on 5/12. 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.
Wed 6/255:08 pmONT - BWI
1 stop9h 39mDelta
Sat 7/57:05 amBWI - ONT
1 stop8h 12mDelta
Deal found 5/12$357

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 May 13, 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 - IAD

ONTIAD

Ontario

Sat 5/24

5:15 pm-5:55 am

1 stop9h 40m

Washington, D.C. Dulles Intl

Sat 5/31

7:25 am-4:20 pm

1 stop11h 55m

$200

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Mon 6/2

12:59 am-12:00 pm

1 stop8h 01m

Washington, D.C. Reagan-National

Fri 6/6

6:00 pm-11:50 pm

1 stop8h 50m

$209

OntarioBaltimore

ONT - BWI

ONTBWI

Ontario

Fri 5/23

12:59 am-4:53 pm

1 stop12h 54m

Baltimore/Washington

Mon 6/2

5:20 pm-11:50 pm

1 stop9h 30m

$210

OntarioWashington, D.C.

ONT - DCA

ONTDCA

Ontario

Sat 5/24

12:18 pm-11:43 pm

1 stop8h 25m

Washington, D.C. Reagan-National

Fri 5/30

6:00 am-11:08 am

1 stop8h 08m

$326

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 5/29

7:20 pm-7:36 am

1 stop9h 16m

Washington, D.C. Dulles Intl

Tue 6/3

9:00 am-3:50 pm

1 stop9h 50m

$326

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 5/24

1:10 pm-11:53 pm

1 stop7h 43m

Washington, D.C. Dulles Intl

Tue 6/3

6:00 am-11:08 am

1 stop8h 08m

$327

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 5/23

10:51 am-12:02 am

2 stops10h 11m

Washington, D.C. Dulles Intl

Fri 5/30

5:07 pm-9:58 pm

1 stop7h 51m

$333

OntarioBaltimore

ONT - BWI

ONTBWI

Ontario

Thu 6/26

9:20 pm-5:10 am

Nonstop4h 50m

Baltimore/Washington

Sat 7/5

8:55 pm-11:15 pm

Nonstop5h 20m

$337

OntarioBaltimore

ONT - BWI

ONTBWI

Ontario

Wed 6/11

4:45 pm-6:29 am

1 stop10h 44m

Baltimore/Washington

Mon 6/16

5:20 pm-11:50 pm

1 stop9h 30m

$342

OntarioBaltimore

ONT - BWI

ONTBWI

Ontario

Wed 6/25

5:08 pm-5:47 am

1 stop9h 39m

Baltimore/Washington

Sat 7/12

7:10 am-12:14 pm

1 stop8h 04m

$357

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/10

Showing 1-10 of 42 results
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Compare providers for flights from Ontario to Washington, D.C.

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 Ontario to Washington, D.C. in May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
CheapOairPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightnetworkPrice Accuracy-Trust Score*3 stars
PricelinePrice Accuracy2 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 Ontario-Washington, D.C. flights, users find the pricing of CheapOair to be most consistent on Cheapflights vs. CheapOair Users can find the same prices on Ontario-Washington, D.C. flight deals on Cheapflights vs. CheapOair >95% of the time. Price accuracy is based on data collected from Ontario-Washington, D.C. flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-Washington, D.C. flights, Cheapflights users trust CheapOair the most. CheapOair 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 Ontario-Washington, D.C. 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 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 May 9, 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 $309). Flying from Ontario to Washington, D.C. in June is currently the most expensive (average of $371). 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 May 13, 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 May 11, 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.

Rainfall in Washington, D.C. by month

Plan your trip to Washington, D.C. by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Washington, D.C. ranges from 2.6 - 4.0 inches per month. May is typically the wettest month, when rainfall can reach 4.0 in. February is typically the driest time to visit Washington, D.C. when rainfall is around 2.6 in.

Temperature in Washington, D.C. by month

Plan your trip to Washington, D.C. by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Washington, D.C., use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 35.6 F).

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 May 13, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest and Delta from Ontario to Washington, D.C. by reading reviews from past customers. 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
10,000 reviews

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

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

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

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
4,290 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

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
7,950 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,432 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

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
8,724 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Food

7.1

Crew

8.5

Overall

8.0

Boarding

8.1

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.

  • 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 $200. Other airlines that can offer you cheap pricing are Delta, from $326, and Alaska Airlines, from $326. Users have found that Frontier is 45% 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 $99. Users have also found prices from $158 and $163 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 - Baltimore/Washington or Ontario - Washington, D.C. Reagan-National as they are the most popular.

  • 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 $309). Flying from Ontario to Washington, D.C. in June is currently the most expensive (average of $371). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
Alexandria
Arlington
Woodbridge
Tysons
Springfield
Fairfax
Rockville
Fredericksburg
Silver Spring
Linthicum Heights
Gaithersburg
Falls Church
Laurel
Easton
Towson
Herndon
Bowie
National Harbor
Oxon Hill
Reston

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Alternative routes for Ontario to Washington, D.C.

See prices for flight routes from nearby airports that may be better suited for you.
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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 May 13, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$121Average$183FlexibilityNo cancel feeOn-time65%
FrontierCheapest$146Average$288FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$256Average$465FlexibilityNo cancel feeOn-time69%
DeltaCheapest$286Average$420FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$286Average$522FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$332Average$474FlexibilityNo cancel feeOn-time63%

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