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Dulles Intl

$90+ 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 4/23. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — IAD
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
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 January 26, 2026.

This Kiwi.com deal was found by Cheapflights users on 1/25. 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 2/192:06 pm
ONT
-
IAD
1 stop16h 19m
Frontier
Sun 2/227:20 pm
IAD
-
ONT
2 stops45h 32m
Frontier
Deal found 1/25$267
This Kiwi.com deal was found by Cheapflights users on 1/24. 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.
Wed 4/15:18 pm
ONT
-
IAD
1 stop13h 45m
Multiple Airlines
Mon 4/610:25 pm
IAD
-
ONT
2 stops20h 58m
Multiple Airlines
Deal found 1/24$283
This Kiwi.com deal was found by Cheapflights users on 1/25. 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.
Fri 2/202:21 pm
ONT
-
IAD
2 stops16h 13m
Multiple Airlines
Sun 2/227:20 pm
IAD
-
ONT
1 stop22h 10m
Multiple Airlines
Deal found 1/25$285
This eDestinos deal was found by Cheapflights users on 1/24. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/316:15 am
ONT
-
IAD
2 stops39h 21m
Frontier
Mon 4/610:25 pm
IAD
-
ONT
2 stops49h 35m
Frontier
Deal found 1/24$292
This Delta deal was found by Cheapflights users on 1/24. 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 2/2810:20 pm
ONT
-
IAD
1 stop7h 53m
Delta
Wed 3/47:30 am
IAD
-
ONT
1 stop9h 24m
Delta
Deal found 1/24$297
This Delta deal was found by Cheapflights users on 1/23. 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 2/1410:20 pm
ONT
-
IAD
1 stop8h 34m
Delta
Sat 2/217:15 am
IAD
-
ONT
1 stop7h 47m
Delta
Deal found 1/23$298
This American Airlines deal was found by Cheapflights users on 1/24. 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 4/159:24 am
ONT
-
IAD
2 stops11h 04m
American Airlines
Tue 4/217:00 am
IAD
-
ONT
2 stops14h 24m
American Airlines
Deal found 1/24$307
This Delta deal was found by Cheapflights users on 1/24. 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 2/261:10 pm
ONT
-
IAD
1 stop7h 36m
Delta
Tue 3/33:42 pm
IAD
-
ONT
1 stop8h 23m
Delta
Deal found 1/24$308
This American Airlines deal was found by Cheapflights users on 1/25. 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 4/159:24 am
ONT
-
IAD
2 stops11h 04m
American Airlines
Wed 4/225:55 pm
IAD
-
ONT
1 stop7h 40m
American Airlines
Deal found 1/25$310
This American Airlines deal was found by Cheapflights users on 1/26. 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 2/196:00 am
ONT
-
IAD
1 stop7h 50m
American Airlines
Wed 2/255:37 pm
IAD
-
ONT
1 stop8h 12m
American Airlines
Deal found 1/26$312
This Southwest deal was found by Cheapflights users on 1/25. 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.
Sat 2/2110:05 am
ONT
-
IAD
1 stop8h 40m
Southwest
Tue 2/249:05 am
IAD
-
ONT
2 stops10h 50m
Southwest
Deal found 1/25$313

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 January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

Expedia
3 stars

Round-trip from

$267
(Kiwi.com)

One-way from

$90
(Frontier)

Popular in

January

Cheapest in

July

Average price

$807
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. 19% potential increase in price ($118 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($30 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 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 January 26, 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

Ontario

Fly to

Dulles Intl

Route

Depart

Return

Price

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 4/25

7:05 am-7:56 pm

1 stop9h 51m

Washington, D.C. Dulles Intl

Sat 5/2

6:00 am-11:36 am

1 stop8h 36m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 4/15

12:49 pm-12:42 am

1 stop8h 53m

Washington, D.C. Dulles Intl

Wed 4/22

7:00 am-1:39 pm

1 stop9h 39m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 2/24

1:10 pm-11:46 pm

1 stop7h 36m

Washington, D.C. Dulles Intl

Tue 3/3

3:42 pm-9:05 pm

1 stop8h 23m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

1:15 pm-12:21 am

1 stop8h 06m

Washington, D.C. Dulles Intl

Wed 3/4

12:24 pm-9:05 pm

2 stops11h 41m

$302

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 2/23

6:37 pm-5:27 am

1 stop7h 50m

Washington, D.C. Dulles Intl

Mon 3/2

4:10 pm-10:57 pm

1 stop9h 47m

$319

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 2/19

1:15 pm-12:21 am

1 stop8h 06m

Washington, D.C. Dulles Intl

Mon 2/23

7:30 am-1:54 pm

1 stop9h 24m

$319

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 2/16

7:05 pm-11:00 am

2 stops12h 55m

Washington, D.C. Dulles Intl

Thu 2/19

2:03 pm-9:24 pm

1 stop10h 21m

$324

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 2/23

10:20 pm-9:13 am

1 stop7h 53m

Washington, D.C. Dulles Intl

Mon 3/2

2:17 pm-11:49 pm

2 stops12h 32m

$324

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 2/26

12:02 pm-5:40 am

1 stop14h 38m

Washington, D.C. Dulles Intl

Tue 3/3

7:05 am-3:08 pm

1 stop11h 03m

$346

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 2/25

1:10 pm-11:46 pm

1 stop7h 36m

Washington, D.C. Dulles Intl

Tue 3/3

3:42 pm-9:05 pm

1 stop8h 23m

$357

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/24

Showing 1-10 of 20 results
1
2

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 January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star

*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 Expedia the most. Expedia 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

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Dulles Intl. Price data was last updated on January 23, 2026.

The price you pay for your flight from Ontario to Washington, D.C. Dulles Intl Airport may vary depending on when you book. For the best chance of a lower fare, look to book 54 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. 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 January 26, 2026.
Read reviews from past customers who have flown Southwest, Delta, and United 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
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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
4,268 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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
8,111 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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
9,199 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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
7.2
Good
11,189 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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
3,058 reviews
Southwest
8.0
Very good
4,268 reviews

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Overall

8.0

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 Delta and United Airlines fly from Ontario to Washington, D.C. Dulles Intl Airport in about 7h 50m. The time it takes to get you to your destination can typically vary by up to 2h 01m. 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 $187. Other airlines that can offer you cheap pricing are American Airlines, from $278, and United Airlines, from $298. Users have found that Frontier is 61% 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
Fredericksburg
Hanover
Linthicum Heights
Rockville
Laurel
Towson
Manassas
Largo
Bowie
McLean
Clinton
Upper Marlboro

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.
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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 January 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$187Average$295FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$278Average$396FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$298Average$496FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$318Average$458FlexibilityNo cancel feeOn-time63%
DeltaCheapest$318Average$426FlexibilityNo cancel feeOn-timeN/A

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