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Cheap flights from Seattle to Washington, D.C. from £102

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 5/8. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — WAS
19 May — 26 May1
1 adult
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. are usually found in January or August, booked 83 days in advance, depart on a Tuesday or Monday and return on a Tuesday

Cheap flight deals from Seattle to Washington, D.C.

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to Washington, D.C.
Explore the most affordable flight options available from Seattle to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 19 April 2026.

Thu 4/616:05
SEA
-
IAD
Nonstop5h 08m
Delta
Wed 10/607:00
IAD
-
SEA
Nonstop5h 45m
Delta
Deal found 17/4£181
Tue 28/713:30
SEA
-
IAD
1 stop8h 25m
United Airlines
Tue 1/912:35
IAD
-
SEA
Nonstop5h 45m
United Airlines
Deal found 15/4£189
Tue 2/623:58
SEA
-
DCA
1 stop7h 57m
American Airlines
Tue 9/617:22
DCA
-
SEA
1 stop9h 54m
American Airlines
Deal found 18/4£195
Tue 2/621:35
SEA
-
IAD
1 stop8h 15m
American Airlines
Tue 9/619:24
IAD
-
SEA
1 stop8h 35m
American Airlines
Deal found 18/4£195
Fri 5/623:05
SEA
-
DCA
1 stop6h 35m
Southwest
Tue 9/618:55
DCA
-
SEA
1 stop8h 25m
Southwest
Deal found 17/4£196
Wed 5/823:00
SEA
-
DCA
1 stop10h 20m
Southwest
Wed 12/818:40
DCA
-
SEA
1 stop7h 55m
Southwest
Deal found 18/4£200
Fri 5/623:30
SEA
-
IAD
Nonstop5h 04m
Alaska Airlines
Tue 9/606:00
IAD
-
SEA
Nonstop5h 46m
Alaska Airlines
Deal found 15/4£200
Mon 14/923:10
SEA
-
IAD
Nonstop5h 02m
United Airlines
Wed 23/917:18
IAD
-
SEA
Nonstop5h 45m
United Airlines
Deal found 16/4£203
Tue 22/918:00
SEA
-
IAD
1 stop8h 25m
United Airlines
Fri 25/917:33
IAD
-
SEA
Nonstop5h 51m
United Airlines
Deal found 16/4£203
Fri 24/723:20
SEA
-
IAD
Nonstop5h 02m
United Airlines
Tue 28/717:38
IAD
-
SEA
1 stop9h 36m
United Airlines
Deal found 15/4£207
Fri 29/519:50
SEA
-
DCA
1 stop23h 08m
Frontier
Fri 5/613:59
DCA
-
SEA
1 stop23h 07m
Frontier
Deal found 14/4£209
Fri 12/623:20
SEA
-
IAD
Nonstop5h 02m
United Airlines
Tue 16/617:38
IAD
-
SEA
1 stop9h 21m
United Airlines
Deal found 17/4£210

Find flight deals from Seattle to Washington, D.C.

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Washington, D.C. (WAS). 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 19 April 2026.

Round-trip from

£181

One-way from

£102

Popular in

June

Cheapest in

January

Average price

£300
Delta
  • Delta
  • 4/6-10/6
  • Nonstop
  • 10h 53m total
  • Seattle to Washington, D.C.
Search Deals
Southwest
  • Southwest
  • 5/8
  • 1 total stop
  • 13h 50m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 1% potential increase in price (£2 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (£3 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 2026
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Seattle to Washington, D.C. 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 858,174 searches. Data last updated 19 April 2026.
Use the filters below to find and compare flights from Seattle to Washington, D.C. that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Thu 4/6

11:05-23:55

1 stop9h 50m

Washington, D.C. Reagan-National

Wed 10/6

16:55-00:30

1 stop10h 35m

£222

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Fri 5/6

07:20-15:28

Nonstop5h 08m

Washington, D.C. Reagan-National

Tue 9/6

16:36-19:30

Nonstop5h 54m

£233

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Tue 2/6

06:00-18:40

2 stops9h 40m

Washington, D.C. Reagan-National

Tue 9/6

18:55-00:20

1 stop8h 25m

£234

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 26/9

15:55-23:55

Nonstop5h 00m

Washington, D.C. Dulles Intl

Sun 4/10

07:10-10:03

Nonstop5h 53m

£237

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 20/5

16:05-00:15

Nonstop5h 10m

Washington, D.C. Dulles Intl

Tue 2/6

07:00-09:44

Nonstop5h 44m

£249

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 7/7

22:40-09:24

1 stop7h 44m

Washington, D.C. Dulles Intl

Tue 21/7

17:55-20:46

Nonstop5h 51m

£251

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Tue 2/6

07:20-15:28

Nonstop5h 08m

Washington, D.C. Reagan-National

Tue 9/6

16:36-19:30

Nonstop5h 54m

£252

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Fri 29/5

06:30-19:55

2 stops10h 25m

Washington, D.C. Reagan-National

Fri 5/6

19:05-00:25

1 stop8h 20m

£263

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 3/9

23:10-07:12

Nonstop5h 02m

Washington, D.C. Dulles Intl

Sun 6/9

08:25-14:22

1 stop8h 57m

£270

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 15/8

22:47-09:28

1 stop7h 41m

Washington, D.C. Dulles Intl

Sat 22/8

06:30-11:34

1 stop8h 04m

£271

Flights are sorted by cheapest return flights first.

Deals found on 18/4

Showing 1-10 of 45 resultsSorted by cheapest first
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Best time to book a flight from Seattle to Washington, D.C.

Have a flexible travel schedule? Discover the best time to fly to Washington, D.C. from Seattle with our price prediction graph.
Estimated return 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.

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

Use this chart to determine the optimal time to book a return flight from Seattle to Washington, D.C.. Price data was last updated on 17 April 2026.

To ensure you get the cheapest price possible for a flight from Seattle to Washington, D.C., you should look to book at least 74 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, January is the cheapest month in which you can book a flight from Seattle to Washington, D.C. (average of £73). Flying from Seattle to Washington, D.C. in March is currently the most expensive (average of £894). 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 WAS?

Find hourly flight availability from Seattle to Washington, D.C.. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 19 April 2026.

One of the essential ways to save on airfare from Seattle to Washington, D.C. is to remain as flexible as possible. Flights that are in the afternoon tend to be the most expensive. A flight in the morning could potentially save you up to 49% on airfare.

Weekly flight availability from Seattle to Washington, D.C.

Explore weekly flight availability from Seattle to Washington, D.C.. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 19 April 2026.

The most flights from SEA to WAS are scheduled on a Saturday (26 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (8 on average).

How much does it cost for a return flight from Seattle to Washington, D.C.?

Related info for your journey

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

    Located just 11.4 mi from the city center, Seattle/Tacoma Intl is the airport most travelers will use when flying to Washington, D.C. from Seattle. Booking flights from Seattle/Tacoma Intl (SEA) to Washington, D.C. should be relatively easy as there are 16 daily outbound flights to Washington, D.C. from 0 different airlines.

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

    Delta, Southwest, and United Airlines can get you from Seattle to Washington, D.C. in just under 5h. Your travel time can differ by up to 4h 50m. Airlines will cover a distance of 2299 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

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

    Consider Iberia (100%), ITA Airways (100%) or Lufthansa (100%) when booking your flight. These represent the most reliable airlines when flying from Seattle to Washington, D.C..

  • Can I find deals for flights from Seattle to Washington, D.C. that include hotel bookings?

    Yes. In addition to deals on Seattle to Washington, D.C. flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Washington, D.C.?

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

  • Can I find deals for business class flights from Seattle to Washington, D.C.?

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

    Currently, January is the cheapest month in which you can book a flight from Seattle to Washington, D.C. (average of £73). Flying from Seattle to Washington, D.C. in March is currently the most expensive (average of £894). 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.?

Book flights to Washington, D.C. if you plan to visit one of these locations
Silver Spring
Hanover
Oxon Hill
Gaithersburg
Woodbridge
Arlington
Alexandria

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Why should you use Cheapflights to find cheap flight tickets from Seattle to Washington, D.C.?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Seattle to Washington, D.C..

Can Cheapflights find flights from Seattle to Washington, D.C. with no change fees?

Need flexible booking options for your flight to Washington, D.C. from Seattle? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from Seattle to Washington, D.C. become cheaper?

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Washington, D.C. from Seattle today and book when prices fit your budget.

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