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Dulles Intl

$139+ 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 4/22. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
May 1 — May 81
Fri 5/1
Fri 5/8
1 adult, Economy
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Find cheap flights from Seattle to Dulles Intl 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 Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or October, booked 44 days in advance, depart on a Wednesday or Thursday and return on a Tuesday

Cheap 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 April 1, 2026.

This Expedia deal was found by Cheapflights users on 3/28. 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.
Fri 6/128:13 pm
SEA
-
IAD
1 stop8h 37m
Frontier
Tue 6/169:20 am
IAD
-
SEA
1 stop28h 15m
Frontier
Deal found 3/28$230
This CheapOair deal was found by Cheapflights users on 3/27. 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.
Mon 6/18:20 pm
SEA
-
IAD
1 stop8h 52m
Frontier
Mon 6/89:12 am
IAD
-
SEA
1 stop28h 23m
Frontier
Deal found 3/27$231
This CheapOair deal was found by Cheapflights users on 3/28. 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.
Thu 6/48:20 pm
SEA
-
IAD
1 stop8h 52m
Frontier
Tue 6/99:20 am
IAD
-
SEA
1 stop28h 15m
Frontier
Deal found 3/28$241
This Delta deal was found by Cheapflights users on 3/31. 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 4/293:59 pm
SEA
-
IAD
Nonstop4h 56m
Delta
Wed 5/67:00 am
IAD
-
SEA
Nonstop5h 54m
Delta
Deal found 3/31$245
This CheapOair deal was found by Cheapflights users on 3/31. 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 6/58:20 pm
SEA
-
IAD
1 stop8h 52m
Frontier
Mon 6/89:12 am
IAD
-
SEA
1 stop28h 23m
Frontier
Deal found 3/31$246
This Expedia deal was found by Cheapflights users on 3/29. 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.
Tue 6/98:13 pm
SEA
-
IAD
1 stop8h 37m
Frontier
Wed 6/109:20 am
IAD
-
SEA
1 stop28h 15m
Frontier
Deal found 3/29$250
This Delta deal was found by Cheapflights users on 3/31. 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 5/23:59 pm
SEA
-
IAD
Nonstop4h 56m
Delta
Sat 5/97:30 am
IAD
-
SEA
1 stop10h 53m
Delta
Deal found 3/31$255
This Delta deal was found by Cheapflights users on 3/31. 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 4/303:59 pm
SEA
-
IAD
Nonstop4h 56m
Delta
Tue 5/57:00 am
IAD
-
SEA
Nonstop5h 54m
Delta
Deal found 3/31$259
This CheapOair deal was found by Cheapflights users on 3/30. 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.
Wed 7/298:13 pm
SEA
-
IAD
1 stop8h 37m
Frontier
Tue 8/49:20 am
IAD
-
SEA
1 stop28h 15m
Frontier
Deal found 3/30$261
This Delta deal was found by Cheapflights users on 3/31. 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.
Tue 4/2810:40 pm
SEA
-
IAD
1 stop10h 25m
Delta
Sat 5/96:00 am
IAD
-
SEA
1 stop9h 19m
Delta
Deal found 3/31$265
This CheapOair deal was found by Cheapflights users on 3/27. 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.
Thu 5/288:20 pm
SEA
-
IAD
1 stop8h 52m
Frontier
Sun 5/319:12 am
IAD
-
SEA
1 stop28h 24m
Frontier
Deal found 3/27$266

Find 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 April 1, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$230
(Expedia)

One-way from

$139
(Kiwi.com)

Popular in

January

Cheapest in

February

Average price

$347

Good round-trip deal

$330 or less

Good one-way deal

$215 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Washington, D.C. Dulles Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Washington, D.C. Dulles Intl flights.
Search Deals
From Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
Search Deals
One-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($52 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($22 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl.
Search Deals

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 April 1, 2026.
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

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 5/9

2:28 pm-12:33 am

1 stop7h 05m

Washington, D.C. Dulles Intl

Tue 5/12

6:15 am-11:39 am

1 stop8h 24m

$275

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 5/1

2:27 pm-12:33 am

1 stop7h 06m

Washington, D.C. Dulles Intl

Tue 5/5

6:30 am-12:25 pm

1 stop8h 55m

$279
Quickest round-trip

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 4/29

3:59 pm-11:55 pm

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sun 5/3

7:00 am-9:54 am

Nonstop5h 54m

$297

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 5/5

7:36 pm-7:02 am

1 stop8h 26m

Washington, D.C. Dulles Intl

Tue 5/12

5:55 pm-8:53 pm

Nonstop5h 58m

$307

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 4/30

3:55 pm-12:09 am

Nonstop5h 14m

Washington, D.C. Dulles Intl

Mon 5/4

6:47 pm-10:26 am

1 stop18h 39m

$327

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 5/7

6:30 am-12:20 am

2 stops14h 50m

Washington, D.C. Dulles Intl

Mon 5/11

4:30 pm-12:55 am

1 stop11h 25m

$332

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 5/8

6:30 am-12:20 am

2 stops14h 50m

Washington, D.C. Dulles Intl

Mon 5/11

4:30 pm-12:55 am

1 stop11h 25m

$332

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 5/2

3:55 pm-12:09 am

Nonstop5h 14m

Washington, D.C. Dulles Intl

Tue 5/5

7:10 am-9:58 am

Nonstop5h 48m

$337

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 6/3

11:30 pm-7:34 am

Nonstop5h 04m

Washington, D.C. Dulles Intl

Sun 6/7

6:00 am-8:46 am

Nonstop5h 46m

$357

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 4/20

3:59 pm-11:55 pm

Nonstop4h 56m

Washington, D.C. Dulles Intl

Fri 4/24

7:00 am-9:54 am

Nonstop5h 54m

$362

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/31

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Seattle 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 Seattle to Dulles Intl in April.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
Trip.comPrice Accuracy1 starTrust 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 Seattle-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 Seattle-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-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 Seattle-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 Seattle-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 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 March 13, 2026.

Booking 44 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, March is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $163). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $288). 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 April 1, 2026.

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 38% on your trip compared to booking a flight in the morning.

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 March 28, 2026.

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.

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

The best insider tips for Seattle to Washington, D.C. Dulles Intl Airport flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to Washington, D.C. Dulles Intl Airport trip
Our travel experts
Robert Schrader

Robert Schrader

Expert on Alaska Airlines

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 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

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 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

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 April 1, 2026.
See what other customers who have flown with Alaska Airlines,Delta, andHawaiian 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
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Alaska Airlines
7.9
Good
12,145 reviews
Alaska Airlines
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Delta
7.9
Good
8,367 reviews
Alaska Airlines
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Hawaiian Airlines
7.8
Good
2,838 reviews
Alaska Airlines
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
United Airlines
7.4
Good
9,529 reviews
Alaska Airlines
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
American Airlines
7.1
Good
11,545 reviews
Alaska Airlines
7.9
Good
12,145 reviews

Boarding

8.1

Crew

8.5

Entertainment

7.0

Comfort

7.8

Overall

7.9

Food

7.0

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.

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 14 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 6 different airlines.

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

    Airlines like United Airlines and Delta fly from Seattle to Washington, D.C. Dulles Intl Airport in about 4h 56m. The time it takes to get you to your destination can typically vary by up to 2h 09m. The distance between Seattle and Washington, D.C. Dulles Intl Airport is about 2299 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

    Frontier, at $126, was found to be the cheapest airline from Seattle to Washington, D.C. Dulles Intl Airport.Alternate airlines to your destination round-trip include Hawaiian Airlines and Delta. Frontier is 70% cheaper than the average price of flights available within the next 90 days to this destination.

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

    The cheapest airlines for a one-way flight from Seattle to Washington, D.C. Dulles Intl Airport are Southwest ($109), Frontier ($117), and Delta ($128).

  • 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: ITA Airways (100%), Ethiopian Air (96%), Brussels Airlines (95%).

  • 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 $149. While the most popular route (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl) can be booked for $297 on average, our data indicates $739 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, March is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $163). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $288). 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.

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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
Owings Mills
Arlington
Springfield
Silver Spring
Herndon
Hyattsville
Hanover
Laurel
Rockville
Upper Marlboro
Fredericksburg
Largo
Bowie
Clinton
Towson
Cordova
Manassas

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Top 6 airlines flying from Seattle to Dulles Intl

Discover the top 6 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 April 1, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$126Average$300FlexibilityNo cancel feeOn-time62%
Hawaiian AirlinesCheapest$138Average$332FlexibilityNo cancel feeOn-time85%
DeltaCheapest$163Average$326FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$220Average$419FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$238Average$425FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$406Average$708FlexibilityNo cancel feeOn-time71%

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