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Dulles Intl

$100+ Cheap flights from Ontario (ONT) to Dulles Intl (IAD)

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 4/16. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — IAD
Apr 12 — Apr 191
Sun 4/12
Sun 4/19
1 adult, Economy
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Cheap flight deals from Ontario to Dulles Intl

Cheapest flights from Ontario to Dulles Intl
Explore the most affordable flight options available from Ontario to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 13, 2026.

This Delta deal was found by Cheapflights users on 3/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/156:00 am
ONT
-
IAD
2 stops14h 55m
Delta
Tue 4/217:00 am
IAD
-
ONT
1 stop9h 39m
Delta
Deal found 3/9$252
This Delta deal was found by Cheapflights users on 3/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/111:53 am
ONT
-
IAD
1 stop9h 02m
Delta
Mon 5/47:00 am
IAD
-
ONT
1 stop9h 39m
Delta
Deal found 3/10$267
This Alaska Airlines deal was found by Cheapflights users on 3/8. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/156:00 am
ONT
-
IAD
1 stop20h 40m
Alaska Airlines
Tue 4/217:00 am
IAD
-
ONT
1 stop19h 59m
Alaska Airlines
Deal found 3/8$285
This Delta deal was found by Cheapflights users on 3/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/2911:53 am
ONT
-
IAD
1 stop9h 02m
Delta
Sun 5/37:00 am
IAD
-
ONT
1 stop9h 39m
Delta
Deal found 3/10$287
This Alaska Airlines deal was found by Cheapflights users on 3/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/146:00 am
ONT
-
IAD
1 stop20h 40m
Alaska Airlines
Tue 4/217:00 am
IAD
-
ONT
1 stop19h 59m
Alaska Airlines
Deal found 3/9$295
This Kiwi.com deal was found by Cheapflights users on 3/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/166:15 am
ONT
-
IAD
1 stop8h 57m
Frontier
Tue 4/218:20 am
IAD
-
ONT
2 stops29h 24m
Frontier
Deal found 3/9$300
This Alaska Airlines deal was found by Cheapflights users on 3/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/2310:39 am
ONT
-
IAD
1 stop10h 30m
Alaska Airlines
Thu 4/307:10 am
IAD
-
ONT
1 stop19h 49m
Alaska Airlines
Deal found 3/9$305
This Delta deal was found by Cheapflights users on 3/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1611:53 am
ONT
-
IAD
1 stop9h 02m
Delta
Tue 4/217:00 am
IAD
-
ONT
1 stop13h 15m
Delta
Deal found 3/9$306
This Alaska Airlines deal was found by Cheapflights users on 3/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:00 am
ONT
-
IAD
1 stop15h 09m
Alaska Airlines
Sun 5/39:00 am
IAD
-
ONT
1 stop27h 45m
Alaska Airlines
Deal found 3/9$310

Find flight deals from Ontario to Dulles Intl

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Dulles Intl (IAD). 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 March 13, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$252
(Delta)

One-way from

$100
(Frontier)

Popular in

January

Cheapest in

July

Average price

$455
Provider with most accurate pricing for Ontario-Washington, D.C. Dulles Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-Washington, D.C. Dulles Intl flights.
Search Deals
From Ontario to Washington, D.C. Dulles Intl
Search Deals
One-way flight from Ontario to Washington, D.C. Dulles Intl
Search Deals
Highest demand for flights based on searches. 23% potential increase in price ($144 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($31 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Dulles Intl 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 March 13, 2026.
Use the filters below to find and compare flights from Ontario to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 4/15

6:00 am-5:40 am

1 stop20h 40m

Washington, D.C. Dulles Intl

Tue 4/21

7:00 am-11:59 pm

1 stop19h 59m

$285
Quickest round-trip

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 5/9

1:20 pm-10:55 pm

1 stop6h 35m

Washington, D.C. Dulles Intl

Tue 5/19

6:20 am-10:15 am

1 stop6h 55m

$337

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 4/23

10:39 am-12:09 am

1 stop10h 30m

Washington, D.C. Dulles Intl

Sat 4/25

7:10 am-2:32 pm

1 stop10h 22m

$355

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 5/1

3:26 pm-5:50 am

1 stop11h 24m

Washington, D.C. Dulles Intl

Mon 5/4

9:00 am-2:32 pm

1 stop32h 32m

$360

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 5/7

11:52 am-12:15 am

1 stop9h 23m

Washington, D.C. Dulles Intl

Sun 5/10

7:00 am-10:34 pm

1 stop18h 34m

$366

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 5/2

10:39 am-12:09 am

1 stop10h 30m

Washington, D.C. Dulles Intl

Mon 5/4

7:20 pm-9:45 am

1 stop17h 25m

$405

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 4/24

3:26 pm-5:50 am

1 stop11h 24m

Washington, D.C. Dulles Intl

Mon 4/27

7:20 pm-10:32 pm

1 stop30h 12m

$430

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 5/6

6:00 am-12:09 am

1 stop15h 09m

Washington, D.C. Dulles Intl

Sun 5/10

7:10 am-9:45 am

1 stop29h 35m

$434

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 4/15

1:27 pm-1:25 am

1 stop8h 58m

Washington, D.C. Dulles Intl

Sat 4/18

4:10 pm-10:45 pm

1 stop9h 35m

$437

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 5/14

12:04 pm-11:59 pm

1 stop8h 55m

Washington, D.C. Dulles Intl

Tue 5/19

6:00 am-3:09 pm

1 stop12h 09m

$464

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/8

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Ontario to Dulles Intl

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 Dulles Intl in March.
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 Ontario-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-Washington, D.C. Dulles Intl Airport 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 Ontario-Washington, D.C. Dulles Intl Airport 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 Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl 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. Dulles Intl Airport

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

Currently, June is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $142). Flying from Ontario to Washington, D.C. Dulles Intl Airport in November is currently the most expensive (average of $267). 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.

Reviews of airlines servicing Dulles Intl

Get insights into the airlines that provide service to Dulles Intl. 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 Dulles Intl. Reviews last updated March 13, 2026.
Read reviews from past customers who have flown Southwest,Delta, andUnited Airlines from Ontario to Washington, D.C. Dulles Intl Airport. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Southwest
8.0
Very good
4,319 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Delta
7.9
Good
8,284 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
United Airlines
7.4
Good
9,418 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
American Airlines
7.1
Good
11,432 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.
Frontier
5.7
Fair
3,032 reviews
Southwest
8.0
Very good
4,319 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Reviews

1 / 20
10.0
Excellent

William Drew,Nov 2025

SJC - HNL

Flight crew was amazing! Usually they're very good on Southwest, but this crew went above and beyond. I have never ever seen so many rounds of drink service on a flight before.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Dulles Intl. 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. Dulles Intl?

    Most people fly from Ontario (ONT) if they book a flight from Ontario to Washington, D.C. Dulles Intl. On average, Ontario has 0 outbound flights to Washington, D.C. Dulles Intl per day from 5 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

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

    Airlines like Alaska Airlines, Southwest, and Delta fly from Ontario to Washington, D.C. Dulles Intl Airport in about 6h 35m. The time it takes to get you to your destination can typically vary by up to 14h 05m. Ontario and Washington, D.C. Dulles Intl Airport are separated by a distance of 2236 mi. This flight may include one or multiple stops.

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

    Cheapflights users have booked flights from Ontario to Washington, D.C. Dulles Intl Airport round-trip from $172. Other airlines that can offer you cheap pricing are Frontier, from $187, and American Airlines, from $278. Users have found that Delta is 63% cheaper than the other options available to this destination.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $71. Southwest flights start at $142 while deals on American Airlines start at $149 one-way.

  • Can I find deals for flights from Ontario to Dulles Intl that include hotel bookings?

    Yes. In addition to deals on Ontario to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to Dulles Intl?

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

  • Can I find deals for business class flights from Ontario to Dulles Intl?

    Yes. Cheapflights offers flight deals from Ontario to Dulles Intl 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. Dulles Intl Airport?

    Currently, June is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $142). Flying from Ontario to Washington, D.C. Dulles Intl Airport in November is currently the most expensive (average of $267). 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. Dulles Intl Airport?

Book flights to Washington, D.C. Dulles Intl Airport if you plan to visit one of these locations
Alexandria
Woodbridge
Tysons
Arlington
Owings Mills
Springfield
Silver Spring
Herndon
Hyattsville
Hanover
Laurel
Rockville
Upper Marlboro
Linthicum Heights
Fredericksburg
Largo
Bowie
Clinton
Towson
College Park

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Ontario to Dulles Intl

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

Top 5 airlines flying from Ontario to Dulles Intl

Discover the top 5 airlines that operate flights from Ontario to Dulles Intl. 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 March 13, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$172Average$426FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$187Average$294FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$278Average$413FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$298Average$487FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$318Average$456FlexibilityNo cancel feeOn-time63%

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