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Dulles Intl

$116+ 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 8/25. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — IAD
Aug 22 — Aug 291
Sat 8/22
Sat 8/29
1 adult, Economy
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Find cheap flights from Ontario to Dulles Intl with Cheapflights

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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 July 23, 2026.

This Kiwi.com deal was found by Cheapflights users on 7/18. 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 8/206:00 am
ONT
-
IAD
2 stops13h 52m
Frontier
Mon 8/248:59 am
IAD
-
ONT
1 stop10h 23m
Frontier
Deal found 7/18$315
This Kiwi.com deal was found by Cheapflights users on 7/21. 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 9/23:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Mon 9/78:39 pm
IAD
-
ONT
2 stops25h 22m
Frontier
Deal found 7/21$317
This Kiwi.com deal was found by Cheapflights users on 7/18. 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.
Tue 8/114:09 pm
ONT
-
IAD
1 stop13h 11m
Frontier
Thu 8/137:48 am
IAD
-
ONT
2 stops26h 44m
Frontier
Deal found 7/18$321
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 8/283:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Sat 8/294:52 pm
IAD
-
ONT
2 stops18h 46m
Frontier
Deal found 7/20$325
This Kiwi.com deal was found by Cheapflights users on 7/20. 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 8/279:33 am
ONT
-
IAD
2 stops10h 19m
Frontier
Sun 8/308:59 am
IAD
-
ONT
1 stop26h 04m
Frontier
Deal found 7/20$327
This Trip.com deal was found by Cheapflights users on 7/18. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/208:17 am
ONT
-
IAD
1 stop7h 12m
Frontier
Thu 8/278:59 am
IAD
-
ONT
1 stop10h 23m
Frontier
Deal found 7/18$329
This Trip.com deal was found by Cheapflights users on 7/22. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/208:17 am
ONT
-
IAD
1 stop7h 12m
Frontier
Tue 8/258:59 am
IAD
-
ONT
1 stop9h 55m
Frontier
Deal found 7/22$331
This Kiwi.com deal was found by Cheapflights users on 7/22. 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 8/193:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Wed 8/268:59 am
IAD
-
ONT
1 stop9h 55m
Frontier
Deal found 7/22$332
This Trip.com deal was found by Cheapflights users on 7/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/263:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Sat 8/298:59 am
IAD
-
ONT
1 stop9h 55m
Frontier
Deal found 7/21$333
This Trip.com deal was found by Cheapflights users on 7/18. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/183:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Mon 8/248:59 am
IAD
-
ONT
1 stop15h 28m
Frontier
Deal found 7/18$335
This Trip.com deal was found by Cheapflights users on 7/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/243:40 pm
ONT
-
IAD
1 stop13h 24m
Frontier
Thu 8/278:59 am
IAD
-
ONT
1 stop10h 23m
Frontier
Deal found 7/21$336
This Kiwi.com deal was found by Cheapflights users on 7/20. 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.
Tue 8/253:13 pm
ONT
-
IAD
2 stops13h 51m
Frontier
Fri 8/288:59 am
IAD
-
ONT
1 stop10h 23m
Frontier
Deal found 7/20$337

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 July 23, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$315
(Kiwi.com)

One-way from

$116
(Trip.com)

Popular in

April

Cheapest in

September

Average price

$469
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. 10% potential increase in price ($68 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($38 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 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 July 23, 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

Tue 9/29

12:12 pm-11:59 pm

1 stop8h 47m

Washington, D.C. Dulles Intl

Tue 10/13

7:02 am-1:16 pm

1 stop9h 14m

$341

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 10/5

10:00 pm-9:12 am

1 stop8h 12m

Washington, D.C. Dulles Intl

Wed 10/21

6:00 am-11:08 am

1 stop8h 08m

$341

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 9/15

12:12 pm-11:59 pm

1 stop8h 47m

Washington, D.C. Dulles Intl

Fri 9/18

5:57 pm-11:16 am

1 stop20h 19m

$401

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 11/18

11:55 am-11:51 pm

1 stop8h 56m

Washington, D.C. Dulles Intl

Fri 11/27

7:00 am-11:27 am

1 stop7h 27m

$420

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 9/14

6:02 am-5:40 am

1 stop20h 38m

Washington, D.C. Dulles Intl

Wed 9/30

7:00 am-2:16 pm

1 stop10h 16m

$421

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 8/13

12:00 pm-12:34 am

1 stop9h 34m

Washington, D.C. Dulles Intl

Thu 8/20

6:00 am-10:42 am

1 stop7h 42m

$423

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 8/26

12:00 pm-11:59 pm

1 stop8h 59m

Washington, D.C. Dulles Intl

Mon 9/14

5:57 pm-7:03 pm

1 stop28h 06m

$431
Quickest round-trip

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sun 11/8

1:17 pm-11:35 pm

1 stop7h 18m

Washington, D.C. Dulles Intl

Sun 11/15

6:00 am-11:27 am

1 stop8h 27m

$445

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 9/5

11:00 am-9:22 pm

1 stop7h 22m

Washington, D.C. Dulles Intl

Sat 9/12

6:42 am-12:12 pm

1 stop8h 30m

$451

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 8/14

5:26 pm-11:59 pm

1 stop27h 33m

Washington, D.C. Dulles Intl

Tue 8/18

6:03 am-1:09 pm

1 stop10h 06m

$456

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/18

Showing 1-10 of 24 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 July.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapOairPrice 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, September is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $284). Flying from Ontario to Washington, D.C. Dulles Intl Airport in April is currently the most expensive (average of $984). 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.

How much does it cost to fly round-trip from Ontario to Washington, D.C. Dulles Intl Airport?

Airfare is typical for this route at the moment.

Ontario to Washington, D.C. Dulles Intl Airport flights typically cost between $308 and $606 in August.
The cheapest round-trip price found within the last 5 days was $315 on Frontier (Aug 20-Aug 24).

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 July 23, 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
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
Southwest
8.0
Very good
4,238 reviews
Southwest
8.0
Very good
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
Delta
7.8
Good
8,479 reviews
Southwest
8.0
Very good
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
United Airlines
7.4
Good
10,024 reviews
Southwest
8.0
Very good
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
American Airlines
7.1
Good
11,832 reviews
Southwest
8.0
Very good
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
Frontier
5.6
Fair
2,770 reviews
Southwest
8.0
Very good
4,238 reviews

Boarding

8.1

Comfort

8.0

Entertainment

7.5

Overall

8.0

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

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 and Delta fly from Ontario to Washington, D.C. Dulles Intl Airport in about 8h 12m. The time it takes to get you to your destination can typically vary by up to 35m. 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 $192, and American Airlines, from $278. Users have found that Delta is 69% 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 $140. American Airlines flights start at $159 while deals on Delta start at $160 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, September is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $284). Flying from Ontario to Washington, D.C. Dulles Intl Airport in April is currently the most expensive (average of $984). 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
Tysons
Arlington
Owings Mills
Springfield
Lanham
Reston
Herndon
Rockville
Chantilly
Hyattsville
Fredericksburg
Falls Church
Hanover
Manassas
Laurel
Sterling
Clinton
Hunt Valley
Cordova

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 July 23, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$172Average$452FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$192Average$295FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$278Average$533FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$314Average$611FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$318Average$448FlexibilityNo cancel feeOn-time63%

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