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Dulles Intl

$147+ Cheap flights from Seattle (SEA) 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 9/6. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
Aug 25 — Sep 11
Mon 8/25
Mon 9/1
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in October or February, booked 36 days in advance, depart on a Thursday or Wednesday and return on a Tuesday

Cheap flight deals from Seattle to Dulles Intl

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) 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 August 20, 2025.

Round-trip from

$249
(Frontier)

One-way from

$147
(Frontier)

Popular in

December

Cheapest in

October

Average price

$397

Good round-trip deal

$315 or less

Good one-way deal

$209 or less
From Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
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One-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
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Highest demand for flights based on searches. 6% potential increase in price ($26 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($11 potential savings vs. average RT price).
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Average for round-trip flights in August 2025
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
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Price to beat on a one-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
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Find flight deals from Seattle to Dulles Intl

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 20, 2025.

This Frontier deal was found by Cheapflights users on 8/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/612:58 pmSEA - IAD
2 stops23h 08mFrontier
Sat 11/88:36 pmIAD - SEA
2 stops18h 37mFrontier
Deal found 8/18$249
This Frontier deal was found by Cheapflights users on 8/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/247:00 amSEA - IAD
2 stops23h 17mFrontier
Fri 9/261:55 pmIAD - SEA
2 stops13h 35mFrontier
Deal found 8/18$255
This Frontier deal was found by Cheapflights users on 8/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/26:12 amSEA - IAD
2 stops15h 03mFrontier
Thu 10/91:07 pmIAD - SEA
2 stops21h 26mFrontier
Deal found 8/18$262
This CheapOair deal was found by Cheapflights users on 8/18. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/1710:16 amSEA - IAD
1 stop22h 43mFrontier
Mon 10/204:45 pmIAD - SEA
2 stops22h 22mFrontier
Deal found 8/18$267
This Vliegwinkel deal was found by Cheapflights users on 8/19. 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 Vliegwinkel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2511:30 pmSEA - IAD
Nonstop5h 03mHawaiian Airlines
Wed 10/17:00 amIAD - SEA
Nonstop5h 40mHawaiian Airlines
Deal found 8/19$269
This iWofly deal was found by Cheapflights users on 8/19. 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 iWofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/44:20 pmSEA - IAD
Nonstop5h 03mAlaska Airlines
Sat 10/118:53 amIAD - SEA
Nonstop5h 45mAlaska Airlines
Deal found 8/19$272
This Trip.com deal was found by Cheapflights users on 8/18. 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 10/24:20 pmSEA - IAD
Nonstop5h 03mHawaiian Airlines
Thu 10/96:25 amIAD - SEA
Nonstop5h 43mHawaiian Airlines
Deal found 8/18$273
This Kissandfly.com deal was found by Cheapflights users on 8/20. 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 Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2211:30 pmSEA - IAD
Nonstop5h 03mHawaiian Airlines
Tue 9/306:09 pmIAD - SEA
Nonstop5h 47mHawaiian Airlines
Deal found 8/20$276
This Alaska Airlines deal was found by Cheapflights users on 8/19. 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.
Fri 9/194:20 pmSEA - IAD
Nonstop5h 03mAlaska Airlines
Sat 9/277:00 amIAD - SEA
Nonstop5h 38mAlaska Airlines
Deal found 8/19$277

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle 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 August 20, 2025.
Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Seattle

Fly to

Dulles Intl

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 10/4

9:55 pm-6:01 am

Nonstop5h 06m

Washington, D.C. Dulles Intl

Mon 10/6

7:35 am-10:28 am

Nonstop5h 53m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 10/13

11:25 pm-7:33 am

Nonstop5h 08m

Washington, D.C. Dulles Intl

Sat 10/18

8:53 am-11:38 am

Nonstop5h 45m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 9/25

11:30 pm-7:33 am

Nonstop5h 03m

Washington, D.C. Dulles Intl

Tue 9/30

7:00 am-9:40 am

Nonstop5h 40m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 9/20

9:55 pm-6:01 am

Nonstop5h 06m

Washington, D.C. Dulles Intl

Fri 9/26

7:35 am-10:16 am

Nonstop5h 41m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 9/17

4:20 pm-12:23 am

Nonstop5h 03m

Washington, D.C. Dulles Intl

Tue 9/23

6:09 pm-8:56 pm

Nonstop5h 47m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 10/11

4:20 pm-12:23 am

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 10/15

6:25 am-9:08 am

Nonstop5h 43m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 11/26

3:15 pm-11:15 pm

Nonstop5h 00m

Washington, D.C. Dulles Intl

Wed 12/3

7:00 am-10:05 am

Nonstop6h 05m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 10/8

4:48 pm-12:40 am

Nonstop4h 52m

Washington, D.C. Dulles Intl

Wed 10/15

7:35 am-10:28 am

Nonstop5h 53m

$277

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 10/19

11:59 pm-11:26 am

1 stop8h 27m

$148

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 12/4

5:15 am-5:05 pm

1 stop8h 50m

$149

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/18

Showing 1-10 of 14 results
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The best insider tips for Seattle to Washington, D.C. Dulles Intl Airport flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Washington, D.C. Dulles Intl Airport trip
Airlines
Alaska Airlines

Saver Fare allows a carry-on bag, unlike many basic economy options.


Alaska Lounge offers fresh seasonal food and craft cocktails, surpassing many competitors.

Read more about Alaska Airlinesby Robert Schrader
United Airlines

Basic Economy allows a personal item only, no carry-on bags unless exceptions apply.


Polaris Business Class offers lie-flat seats and access to exclusive Polaris Lounges.

Read more about United Airlinesby Harriet Baskas
Airports
SEA

Plan to arrive at SEA at least two hours before your flight. Use SEA Spot Saver for advance security screening appointments.

Read more about SEAby Brandon Schultz
IAD

Use the Washington Metro Silver line for a cost-effective way to reach downtown from IAD in under 40 minutes.

Read more about IADby Ramsey Qubein
Our travel experts
Robert Schrader

Robert Schrader

Expert on Alaska Airlines

Robert Schrader

Robert Schrader

One of the web's original travel bloggers, Robert launched his first site Leave Your Daily Hell in 2009. Since then, he's expanded into destination niche sites (one each for Japan, Thailand and Taiwan), in addition to having written for the inflight magazines of Singapore Airlines and Korean Air. Overall, he's visited nearly 100 countries, and flies business as often as possible.

Read more
Harriet Baskas

Harriet Baskas

Expert on United Airlines

Harriet Baskas

Harriet Baskas

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Read more
Ramsey Qubein

Ramsey Qubein

Expert on IAD

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle 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 Seattle to Washington, D.C. Dulles Intl Airport

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

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Dulles Intl. Price data was last updated on August 8, 2025.

Booking 36 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, July is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $303). Flying from Seattle to Washington, D.C. Dulles Intl Airport in April is currently the most expensive (average of $337). 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 SEA to IAD?

Find hourly flight availability from Seattle to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 20, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 45% on your trip compared to booking a flight at noon.

What is the cheapest day to fly from Seattle to Washington, D.C. Dulles Intl Airport?

Use this chart to determine the cheapest time to fly round-trip from Seattle to Dulles Intl. Price data was last updated on August 17, 2025.

Travelers seeking maximum savings on their Seattle to Washington, D.C. Dulles Intl Airport flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

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 August 20, 2025.
See what other customers who have flown with Alaska Airlines, Delta, and Hawaiian Airlines from Seattle to Washington, D.C. Dulles Intl Airport have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,982 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Hawaiian Airlines
7.8
Good
2,670 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
United Airlines
7.4
Good
8,928 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.0

Food

7.1

Overall

8.0

Boarding

8.1

Crew

8.5

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

Find useful and relevant information for your journey from Seattle 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 Seattle to Washington, D.C. Dulles Intl?

    If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 16 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 5 different airlines.

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

    Airlines like Delta, Hawaiian Airlines, and Alaska Airlines fly from Seattle to Washington, D.C. Dulles Intl Airport in about 5h 03m. The time it takes to get you to your destination is usually consistent. The distance between Seattle and Washington, D.C. Dulles Intl Airport is about 2299 mi. Most flights are nonstop.

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

    Hawaiian Airlines, at $143, was found to be the cheapest airline from Seattle to Washington, D.C. Dulles Intl Airport.Alternate airlines to your destination round-trip include Delta and United Airlines. Hawaiian Airlines is 64% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Austrian Airlines (82%), Brussels Airlines (82%), Lufthansa (78%).

  • What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?

    Looking at all options, your cheapest flight can be booked for $148. While the most popular route (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl) can be booked for $273 on average our data indicates $953 when flying from Seattle to Washington, D.C. Dulles Intl Airport.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Seattle 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 Seattle to Washington, D.C. Dulles Intl Airport?

    Currently, July is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $303). Flying from Seattle to Washington, D.C. Dulles Intl Airport in April is currently the most expensive (average of $337). 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
Woodbridge
Arlington
Alexandria
Tysons
Silver Spring
Springfield
Fredericksburg
Gaithersburg
Towson
Linthicum Heights
Fairfax
Manassas
Falls Church
Laurel
Rockville
Oxon Hill
National Harbor
Dundalk
Waldorf
Bowie

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Alternative routes for Seattle 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 Seattle to Dulles Intl

Discover the top 5 airlines that operate flights from Seattle 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 August 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$143Average$332FlexibilityNo cancel feeOn-time85%
DeltaCheapest$201Average$377FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$237Average$442FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$256Average$486FlexibilityNo cancel feeOn-time71%
Alaska AirlinesCheapest$261Average$420FlexibilityNo cancel feeOn-time75%

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