Find flights
Deals
When to book
Airlines
FAQs

Cheap flights from Seattle to Washington, D.C. Dulles Intl Airport from C$ 175

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 31/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
11 Apr — 18 Apr1
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 77 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 12 March 2026.

Mon 30/39:40 p.m.
SEA
-
IAD
Nonstop5h 00m
Alaska Airlines
Mon 6/47:11 p.m.
IAD
-
SEA
Nonstop5h 51m
Alaska Airlines
Deal found 8/3C$ 295
Wed 22/48:00 a.m.
SEA
-
IAD
Nonstop5h 11m
United Airlines
Wed 29/412:55 p.m.
IAD
-
SEA
1 stop9h 47m
United Airlines
Deal found 10/3C$ 296
Tue 28/43:55 p.m.
SEA
-
IAD
Nonstop5h 14m
Alaska Airlines
Wed 29/47:10 a.m.
IAD
-
SEA
Nonstop5h 48m
Alaska Airlines
Deal found 10/3C$ 297
Thu 16/42:39 p.m.
SEA
-
IAD
1 stop6h 53m
United Airlines
Tue 21/45:55 p.m.
IAD
-
SEA
Nonstop5h 58m
United Airlines
Deal found 7/3C$ 300
Thu 7/510:41 p.m.
SEA
-
IAD
Nonstop5h 09m
United Airlines
Mon 1/63:15 p.m.
IAD
-
SEA
1 stop9h 44m
United Airlines
Deal found 7/3C$ 304
Wed 1/48:00 a.m.
SEA
-
IAD
Nonstop5h 11m
United Airlines
Mon 6/45:41 p.m.
IAD
-
SEA
1 stop9h 05m
United Airlines
Deal found 8/3C$ 308
Thu 23/43:59 p.m.
SEA
-
IAD
Nonstop4h 56m
Delta
Tue 28/47:00 a.m.
IAD
-
SEA
Nonstop5h 54m
Delta
Deal found 10/3C$ 310
Thu 16/49:40 p.m.
SEA
-
IAD
Nonstop5h 00m
Alaska Airlines
Fri 24/47:20 p.m.
IAD
-
SEA
Nonstop5h 45m
Alaska Airlines
Deal found 10/3C$ 311
Wed 22/43:55 p.m.
SEA
-
IAD
Nonstop5h 14m
Alaska Airlines
Sun 26/47:10 a.m.
IAD
-
SEA
Nonstop5h 48m
Alaska Airlines
Deal found 11/3C$ 318
Thu 16/41:55 p.m.
SEA
-
IAD
1 stop7h 25m
Southwest
Wed 22/44:30 p.m.
IAD
-
SEA
1 stop9h 00m
Southwest
Deal found 11/3C$ 319
Wed 8/42:39 p.m.
SEA
-
IAD
1 stop6h 53m
United Airlines
Tue 14/45:55 p.m.
IAD
-
SEA
Nonstop5h 58m
United Airlines
Deal found 9/3C$ 320
Fri 17/47:05 p.m.
SEA
-
IAD
1 stop7h 23m
United Airlines
Tue 21/45:55 p.m.
IAD
-
SEA
Nonstop5h 58m
United Airlines
Deal found 10/3C$ 322

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 12 March 2026.

Round-trip from

C$ 295

One-way from

C$ 175

Popular in

January

Cheapest in

February

Average price

C$ 568

Good round-trip deal

C$ 322 or less

Good one-way deal

C$ 528 or less
Alaska Airlines
  • Alaska Airlines
  • 30/3-4/4
  • Nonstop
  • 10h 53m total
  • Seattle to Washington, D.C.
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 31/3
  • Nonstop
  • 5h 02m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (C$ 104 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 March 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 629,999 searches. Data last updated 12 March 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

Fri 24/4

11:14 p.m.-10:18 a.m.

1 stop8h 04m

Washington, D.C. Dulles Intl

Mon 27/4

5:07 p.m.-9:50 p.m.

1 stop7h 43m

C$ 323

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 23/4

5:30 a.m.-3:50 p.m.

1 stop7h 20m

Washington, D.C. Dulles Intl

Sun 26/4

5:50 a.m.-10:25 a.m.

1 stop7h 35m

C$ 405

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 24/3

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

Nonstop5h 00m

Washington, D.C. Dulles Intl

Tue 7/4

7:11 p.m.-10:02 p.m.

Nonstop5h 51m

C$ 405

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 20/5

8:10 a.m.-4:22 p.m.

Nonstop5h 12m

Washington, D.C. Dulles Intl

Tue 26/5

5:55 p.m.-8:46 p.m.

Nonstop5h 51m

C$ 407

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 28/4

3:55 p.m.-12:09 a.m.

Nonstop5h 14m

Washington, D.C. Dulles Intl

Wed 29/4

6:56 p.m.-5:32 p.m.

1 stop25h 36m

C$ 437

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 30/4

8:00 a.m.-12:20 a.m.

1 stop13h 20m

Washington, D.C. Dulles Intl

Mon 4/5

5:55 a.m.-8:05 p.m.

2 stops17h 10m

C$ 447

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 8/4

2:39 p.m.-12:32 a.m.

1 stop6h 53m

Washington, D.C. Dulles Intl

Tue 14/4

1:10 p.m.-7:00 p.m.

1 stop8h 50m

C$ 485

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 10/4

7:05 p.m.-5:28 a.m.

1 stop7h 23m

Washington, D.C. Dulles Intl

Thu 16/4

5:20 p.m.-10:33 p.m.

1 stop8h 13m

C$ 485

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 15/4

8:25 a.m.-11:40 p.m.

2 stops12h 15m

Washington, D.C. Dulles Intl

Mon 20/4

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

1 stop11h 25m

C$ 512

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 4/6

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

Nonstop5h 06m

Washington, D.C. Dulles Intl

Tue 9/6

7:37 p.m.-9:19 a.m.

1 stop16h 42m

C$ 525

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/3

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

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 6 March 2026.

Booking 65 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$ 215). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 390). 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 12 March 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 12 March 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
2,838 reviews
Check prices

Entertainment

7.1

Crew

8.5

Comfort

7.7

Food

6.9

Boarding

8.0

Overall

7.8

Reviews

1 / 20
6.0
Good

Patrick,Feb 2026

SEA - PHX

Was not able to check in online, had to go to multiple lines at airport to get boarding pass and was not able to get a seat without going to the gate, wound up in middle in the back.
Hawaiian Airlines
7.8
Good
2,838 reviews
Hawaiian Airlines
7.8
Good
2,838 reviews
Check prices

Entertainment

7.1

Crew

8.5

Comfort

7.7

Food

6.9

Boarding

8.0

Overall

7.8

Reviews

1 / 20
6.0
Good

Patrick,Feb 2026

SEA - PHX

Was not able to check in online, had to go to multiple lines at airport to get boarding pass and was not able to get a seat without going to the gate, wound up in middle in the back.

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 12 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?

    Delta, Southwest, and Alaska Airlines can get you from Seattle to Washington, D.C. Dulles Intl Airport in just under 5h. Your travel time can differ by up to 3h 04m. 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 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$ 356 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: Brussels Airlines (98%), Austrian Airlines (98%), Avianca (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$ 732, our data shows the cheapest flight currently is C$ 322. When looking at the most popular route, (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl), you can expect to pay C$ 585 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$ 215). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of C$ 390). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 12 March 2026.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapestC$ 356AverageC$ 356FlexibilityNo cancel feeOn-time85%
Search Hawaiian Airlines flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travelers can enjoy low prices and a wide availability of flights to their desired destinations.

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

900+ travel sites are searched through when a user searches for a flight using Cheapflights. From the search interface, users can use filters to choose airlines, airports, flight times, cabin classes and more to their preference. Book your flight to Dulles Intl from Seattle today with Cheapflights!

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?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.