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Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 177

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 24/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
26 Feb — 5 Mar1
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 October or February, booked 41 days in advance, depart on a Thursday or Saturday and return on a Monday

Cheap flight deals from Seattle to Dulles Intl

Enter your travel dates to find the best prices.

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 27 January 2026.

Wed 25/29:27 a.m.
SEA
-
IAD
Nonstop4h 53m
Alaska Airlines
Sun 8/37:05 a.m.
IAD
-
SEA
Nonstop6h 00m
Alaska Airlines
Deal found 26/1C$ 325
Fri 27/212:25 p.m.
SEA
-
IAD
1 stop7h 56m
United Airlines
Mon 2/35:55 p.m.
IAD
-
SEA
Nonstop6h 01m
United Airlines
Deal found 25/1C$ 333
Thu 5/37:10 p.m.
SEA
-
IAD
1 stop7h 07m
United Airlines
Sun 8/35:55 p.m.
IAD
-
SEA
Nonstop6h 01m
United Airlines
Deal found 26/1C$ 338
Tue 17/39:27 a.m.
SEA
-
IAD
Nonstop4h 53m
Hawaiian Airlines
Tue 24/37:11 p.m.
IAD
-
SEA
Nonstop5h 51m
Hawaiian Airlines
Deal found 26/1C$ 351
Wed 13/53:53 p.m.
SEA
-
IAD
Nonstop5h 06m
Alaska Airlines
Thu 28/56:00 a.m.
IAD
-
SEA
Nonstop5h 46m
Alaska Airlines
Deal found 26/1C$ 352
Tue 17/35:30 a.m.
SEA
-
IAD
1 stop8h 01m
American Airlines
Tue 24/35:00 a.m.
IAD
-
SEA
1 stop9h 27m
American Airlines
Deal found 26/1C$ 355
Fri 27/28:17 a.m.
SEA
-
IAD
Nonstop5h 02m
United Airlines
Sat 7/35:55 p.m.
IAD
-
SEA
Nonstop6h 01m
United Airlines
Deal found 26/1C$ 357
Wed 18/33:55 p.m.
SEA
-
IAD
Nonstop4h 54m
Delta
Sat 21/37:00 a.m.
IAD
-
SEA
Nonstop6h 03m
Delta
Deal found 27/1C$ 359
Sat 21/23:40 p.m.
SEA
-
IAD
Nonstop4h 54m
Delta
Sat 28/27:30 a.m.
IAD
-
SEA
Nonstop5h 59m
Delta
Deal found 25/1C$ 364
Tue 28/47:40 p.m.
SEA
-
IAD
1 stop19h 01m
Alaska Airlines
Tue 5/59:00 a.m.
IAD
-
SEA
Nonstop5h 47m
Alaska Airlines
Deal found 27/1C$ 366
Thu 2/47:05 p.m.
SEA
-
IAD
1 stop7h 23m
United Airlines
Sun 5/45:55 p.m.
IAD
-
SEA
Nonstop5h 58m
United Airlines
Deal found 26/1C$ 371

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 27 January 2026.

Round-trip from

C$ 325

One-way from

C$ 177

Popular in

January

Cheapest in

October

Average price

C$ 900
United Airlines
  • United Airlines
  • 24/2-3/3
  • Nonstop
  • 11h 03m total
  • Seattle to Washington, D.C.
Search Deals
Southwest
  • Southwest
  • 28/2
  • 1 total stop
  • 7h 30m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 13% potential increase in price (C$ 125 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (C$ 41 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 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 27 January 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

Seattle

Fly to

Dulles Intl

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 30/4

10:00 a.m.-6:20 p.m.

Nonstop5h 20m

Washington, D.C. Dulles Intl

Sun 3/5

7:10 a.m.-9:58 a.m.

Nonstop5h 48m

C$ 352

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 6/3

7:10 p.m.-5:17 a.m.

1 stop7h 07m

Washington, D.C. Dulles Intl

Tue 10/3

2:12 p.m.-9:14 p.m.

1 stop10h 02m

C$ 352

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 3/3

9:27 a.m.-5:20 p.m.

Nonstop4h 53m

Washington, D.C. Dulles Intl

Tue 10/3

6:20 p.m.-9:28 a.m.

1 stop18h 08m

C$ 366

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 17/3

9:27 a.m.-5:20 p.m.

Nonstop4h 53m

Washington, D.C. Dulles Intl

Tue 24/3

6:22 p.m.-9:27 a.m.

1 stop18h 05m

C$ 393

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 4/5

11:14 p.m.-7:23 a.m.

Nonstop5h 09m

Washington, D.C. Dulles Intl

Fri 8/5

5:55 p.m.-8:53 p.m.

Nonstop5h 58m

C$ 412

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 16/4

1:55 p.m.-12:20 a.m.

1 stop7h 25m

Washington, D.C. Dulles Intl

Mon 20/4

4:30 p.m.-12:55 a.m.

1 stop11h 25m

C$ 427

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 16/4

8:00 a.m.-4:11 p.m.

Nonstop5h 11m

Washington, D.C. Dulles Intl

Mon 20/4

4:10 p.m.-11:27 p.m.

1 stop10h 17m

C$ 435

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 17/5

3:53 p.m.-11:59 p.m.

Nonstop5h 06m

Washington, D.C. Dulles Intl

Tue 26/5

5:33 p.m.-8:27 p.m.

Nonstop5h 54m

C$ 441

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 16/2

9:45 p.m.-5:40 a.m.

Nonstop4h 55m

Washington, D.C. Dulles Intl

Mon 23/2

7:05 a.m.-10:05 a.m.

Nonstop6h 00m

C$ 441

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 16/4

3:59 p.m.-11:55 p.m.

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sun 19/4

7:00 a.m.-9:54 a.m.

Nonstop5h 54m

C$ 455

Flights are sorted by cheapest round-trip flights first.

Deals found on 26/1

Showing 1-10 of 23 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 23 January 2026.

Booking 41 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$ 196). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 400). 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 27 January 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 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 27 January 2026.
Read reviews from past customers who have flown 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.
Hawaiian Airlines
7.8
Good
2,829 reviews
Check prices

Entertainment

7.1

Crew

8.5

Food

6.9

Overall

7.8

Comfort

7.7

Boarding

8.0

Reviews

1 / 20
10.0
Excellent

Brett,Dec 2025

LAX - EUG

Not full, very low cost upgrades, and a good selection of snack boxes.
Hawaiian Airlines
7.8
Good
2,829 reviews
Hawaiian Airlines
7.8
Good
2,829 reviews
Check prices

Entertainment

7.1

Crew

8.5

Food

6.9

Overall

7.8

Comfort

7.7

Boarding

8.0

Reviews

1 / 20
10.0
Excellent

Brett,Dec 2025

LAX - EUG

Not full, very low cost upgrades, and a good selection of snack boxes.

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 8 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 1 airline.

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

    United Airlines and Delta can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 4h 56m. Your travel time will be generally consistent. Seattle and Washington, D.C. Dulles Intl Airport are separated by a distance of 3700 km. All flights are typically direct.

  • What is the cheapest airline to fly 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 Hawaiian Airlines. Our recent data shows that you can find tickets from as low as C$ 359 on this airline. Hawaiian Airlines is 37% 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 (100%), Brussels Airlines (100%), Avianca (98%).

  • 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$ 196). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 400). 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
Silver Spring
Warrenton
Winchester
Hanover
Fairfax
Reston
Ellicott City
Oxon Hill
Gaithersburg
Arlington
Herndon
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 airline flying from Seattle to Dulles Intl

Discover the top airline 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 27 January 2026.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapestC$ 359AverageC$ 359FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

Fly with Cheapflights

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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.

Can Cheapflights notify me if prices for flights from Seattle to Dulles Intl become cheaper?

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