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Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 196

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 16/1. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
27 Nov — 4 Dec1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or October, booked 60 days in advance, depart on a Thursday or Saturday and return on a Tuesday

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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 28 October 2025.

Sat 13/123:30 p.m.SEA - IAD
Nonstop4h 57mDelta
Thu 8/17:30 a.m.IAD - SEA
Nonstop5h 59mDelta
Deal found 26/10C$ 347
Fri 12/128:10 a.m.SEA - IAD
Nonstop5h 08mUnited Airlines
Mon 15/125:55 p.m.IAD - SEA
Nonstop5h 59mUnited Airlines
Deal found 28/10C$ 355
Tue 9/127:59 p.m.SEA - IAD
1 stop18h 31mAlaska Airlines
Thu 11/125:37 p.m.IAD - SEA
1 stop9h 35mAlaska Airlines
Deal found 28/10C$ 358
Thu 4/123:30 p.m.SEA - IAD
Nonstop4h 57mDelta
Tue 9/127:15 a.m.IAD - SEA
Nonstop5h 57mDelta
Deal found 27/10C$ 359
Sat 13/1210:40 a.m.SEA - IAD
1 stop7h 38mUnited Airlines
Thu 8/15:55 p.m.IAD - SEA
Nonstop6h 02mUnited Airlines
Deal found 26/10C$ 361
Tue 30/1210:14 p.m.SEA - IAD
Nonstop4h 59mAlaska Airlines
Tue 6/17:33 a.m.IAD - SEA
Nonstop5h 47mAlaska Airlines
Deal found 28/10C$ 366
Thu 4/128:40 a.m.SEA - IAD
1 stop7h 28mUnited Airlines
Thu 11/125:55 p.m.IAD - SEA
Nonstop5h 59mUnited Airlines
Deal found 27/10C$ 373
Tue 16/123:30 p.m.SEA - IAD
Nonstop4h 57mDelta
Thu 15/17:30 a.m.IAD - SEA
Nonstop5h 59mDelta
Deal found 27/10C$ 375
Mon 17/118:07 p.m.SEA - IAD
1 stop18h 06mAlaska Airlines
Wed 19/117:43 a.m.IAD - SEA
Nonstop5h 52mAlaska Airlines
Deal found 27/10C$ 376
Mon 22/1210:52 a.m.SEA - IAD
1 stop7h 29mUnited Airlines
Tue 6/12:24 p.m.IAD - SEA
1 stop9h 51mUnited Airlines
Deal found 28/10C$ 382
Wed 3/128:40 a.m.SEA - IAD
Nonstop4h 56mAlaska Airlines
Fri 5/127:34 a.m.IAD - SEA
Nonstop6h 01mAlaska Airlines
Deal found 28/10C$ 387

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 28 October 2025.

Round-trip from

C$ 347

One-way from

C$ 196

Popular in

December

Cheapest in

February

Average price

C$ 492

Good round-trip deal

C$ 454 or less

Good one-way deal

C$ 195 or less
Delta
  • Delta
  • 13/12-8/1
  • Nonstop
  • 10h 56m total
  • Seattle to Washington, D.C.
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Delta
  • Delta
  • 16/1
  • Nonstop
  • 4h 50m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 9% potential increase in price (C$ 79 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (C$ 22 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 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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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 629,999 searches. Data last updated 28 October 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

Thu 27/11

4:30 p.m.-12:25 a.m.

Nonstop4h 55m

Washington, D.C. Dulles Intl

Fri 5/12

7:15 a.m.-10:12 a.m.

Nonstop5h 57m

C$ 359

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 5/12

12:35 p.m.-11:15 p.m.

1 stop7h 40m

Washington, D.C. Dulles Intl

Thu 11/12

5:55 p.m.-8:54 p.m.

Nonstop5h 59m

C$ 373

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 17/11

10:29 p.m.-6:23 a.m.

Nonstop4h 54m

Washington, D.C. Dulles Intl

Mon 24/11

7:38 a.m.-10:32 a.m.

Nonstop5h 54m

C$ 375

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 7/2

8:30 a.m.-4:26 p.m.

Nonstop4h 56m

Washington, D.C. Dulles Intl

Wed 18/2

5:51 p.m.-11:46 p.m.

1 stop8h 55m

C$ 376

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 22/12

10:52 a.m.-9:21 p.m.

1 stop7h 29m

Washington, D.C. Dulles Intl

Tue 6/1

2:24 p.m.-9:15 p.m.

1 stop9h 51m

C$ 382

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 27/11

9:35 a.m.-5:34 p.m.

Nonstop4h 59m

Washington, D.C. Dulles Intl

Thu 4/12

7:34 a.m.-10:35 a.m.

Nonstop6h 01m

C$ 415

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 11/12

10:11 p.m.-6:06 a.m.

Nonstop4h 55m

Washington, D.C. Dulles Intl

Sun 14/12

7:34 a.m.-10:35 a.m.

Nonstop6h 01m

C$ 415

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 23/11

8:00 a.m.-4:07 p.m.

Nonstop5h 07m

Washington, D.C. Dulles Intl

Sun 7/12

6:00 p.m.-12:50 a.m.

1 stop9h 50m

C$ 422

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 10/3

9:55 a.m.-5:55 p.m.

Nonstop5h 00m

Washington, D.C. Dulles Intl

Wed 11/3

7:00 a.m.-9:45 a.m.

Nonstop5h 45m

C$ 424

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 7/2

3:20 p.m.-11:10 p.m.

Nonstop4h 50m

Washington, D.C. Dulles Intl

Wed 18/2

12:30 p.m.-10:16 p.m.

1 stop12h 46m

C$ 435

Flights are sorted by cheapest round-trip flights first.

Deals found on 28/10

Showing 1-10 of 24 results
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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 24 October 2025.

Booking 60 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 C$ 200). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 413). 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 28 October 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 evening. If you’re flexible enough to do this you can expect to save up to 74% on your trip compared to booking a flight at noon.

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 28 October 2025.
Read reviews from past customers who have flown Alaska Airlines and Hawaiian Airlines from Seattle 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.
Alaska Airlines
8.0
Very good
11,199 reviews
Check prices

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Overall

8.0

Food

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Alaska Airlines
8.0
Very good
11,199 reviews
Alaska Airlines
8.0
Very good
11,199 reviews
Check prices

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Overall

8.0

Food

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Hawaiian Airlines
7.8
Good
2,794 reviews
Alaska Airlines
8.0
Very good
11,199 reviews
Check prices

Boarding

8.1

Comfort

7.8

Crew

8.5

Entertainment

7.0

Overall

8.0

Food

7.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.

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 18.4 km from the centre of Seattle. There are 11 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 2 different airlines.

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

    Delta, United Airlines, and Alaska Airlines can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 4h 54m. Your travel time can differ by up to 3h 03m. Seattle and Washington, D.C. Dulles Intl Airport are separated by a distance of 3700 km. This flight may include one or multiple stops.

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

    Our cheapest airline available from Seattle to Washington, D.C. Dulles Intl Airport is Alaska Airlines. Our recent data shows that you can find tickets from as low as C$ 267 on this airline. An additional option worth looking into is Hawaiian Airlines, starting at C$ 367. Alaska Airlines is 52% 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: STARLUX Airlines (100%), Avianca (98%), Lufthansa (98%).

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

    While on average a flight from Seattle to Washington, D.C. Dulles Intl Airport is generally C$ 800, our data shows the cheapest flight currently is C$ 193. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 334 for that flight.

  • 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 C$ 200). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 413). 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

Travelling 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
Warrenton
Hanover
Fairfax
Reston
Ellicott City
Oxon Hill
Gaithersburg
Herndon
Arlington
Winchester
Manassas
Fredericksburg
Alexandria
Rockville

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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.
Seattle to Reagan-National flights

Top 2 airlines flying from Seattle to Dulles Intl

Discover the top 2 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 629,999 searches. Data last updated 28 October 2025.
AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapestC$ 267AverageC$ 395FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights
Hawaiian AirlinesCheapestC$ 367AverageC$ 367FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

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How does Cheapflights help users find flights from Seattle to Dulles Intl?

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Why should you use Cheapflights to find cheap flight tickets from Seattle to Dulles Intl?

Cheapflights helps you find that perfect flight to Dulles Intl from Seattle by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Seattle to Dulles Intl with no change fees?

Cheapflights does show flights with no change fees to all users. To see these options for flights from Seattle to Dulles Intl, users can toggle the no change fees filter when performing a flight search.

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