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Cheap flights from Seattle to Washington, D.C. from £94

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 18/2. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — WAS
10 1月 — 17 1月1
1 adult
1 adult, Economy, 0 bags

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Washington, D.C. are usually found in August or July, booked 41 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 11 12月 2025.

週三 31/1223:15SEA - IAD
Nonstop4h 56mUnited Airlines
週四 8/117:55IAD - SEA
Nonstop6h 02mUnited Airlines
Deal found 10/12£239
週三 31/1205:02SEA - IAD
1 stop8h 37mUnited Airlines
週三 7/117:55IAD - SEA
Nonstop6h 02mUnited Airlines
Deal found 10/12£246
週三 31/1205:02SEA - IAD
1 stop8h 37mUnited Airlines
週五 9/117:17IAD - SEA
1 stop8h 26mUnited Airlines
Deal found 10/12£250
週三 31/1215:55SEA - IAD
2 stops14h 54mDelta
週三 7/107:30IAD - SEA
Nonstop5h 59mDelta
Deal found 10/12£263
週三 31/1208:00SEA - IAD
Nonstop5h 06mUnited Airlines
週一 5/108:26IAD - SEA
Nonstop6h 01mUnited Airlines
Deal found 8/12£270
週三 31/1207:35SEA - DCA
Nonstop5h 01mDelta
週一 5/116:44DCA - SEA
Nonstop5h 59mDelta
Deal found 10/12£275
週四 25/1208:00SEA - IAD
Nonstop5h 06mUnited Airlines
週三 7/117:55IAD - SEA
Nonstop6h 02mUnited Airlines
Deal found 9/12£280
週四 25/1223:15SEA - IAD
Nonstop4h 56mUnited Airlines
週四 8/117:17IAD - SEA
1 stop8h 26mUnited Airlines
Deal found 10/12£284
週一 29/1223:15SEA - IAD
Nonstop4h 56mUnited Airlines
週四 8/117:55IAD - SEA
Nonstop6h 02mUnited Airlines
Deal found 8/12£287
週四 25/1209:35SEA - DCA
2 stops10h 15mSouthwest
週四 8/116:05DCA - SEA
1 stop9h 30mSouthwest
Deal found 10/12£299
週三 31/1223:09SEA - DCA
1 stop10h 15mUnited Airlines
週一 5/118:00DCA - SEA
1 stop7h 47mUnited Airlines
Deal found 10/12£302
週四 25/1213:55SEA - DCA
Nonstop5h 04mAlaska Airlines
週二 13/109:59DCA - SEA
1 stop9h 55mAlaska Airlines
Deal found 9/12£302

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 11 12月 2025.

Round-trip from

£168

One-way from

£94

Popular in

January

Cheapest in

August

Average price

£343

Good one-way deal

£333 or less
Alaska Airlines
  • Alaska Airlines
  • 7/1-17/1
  • Nonstop
  • 11h 13m total
  • Seattle to Washington, D.C.
Search Deals
United Airlines
  • United Airlines
  • 18/2
  • 1 total stop
  • 7h 38m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 11% potential increase in price (£29 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£7 potential savings vs. average return price).
Search Deals
Average for round-trip flights in December 2025
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to Washington, D.C. (WAS).
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 11 12月 2025.
Use the filters below to find and compare flights from Seattle to Washington, D.C. that are best for you.

Fly from

Seattle

Fly to

Washington, D.C.

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

週二 10/3

13:56-21:59

Nonstop5h 03m

Washington, D.C. Reagan-National

週二 17/3

08:00-11:10

Nonstop6h 10m

£168

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週四 22/1

08:10-16:16

Nonstop5h 06m

Washington, D.C. Dulles Intl

週六 24/1

13:05-18:14

1 stop8h 09m

£172

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週四 8/1

08:10-16:16

Nonstop5h 06m

Washington, D.C. Dulles Intl

週四 15/1

14:10-21:12

1 stop10h 02m

£172

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週二 17/2

15:20-23:10

Nonstop4h 50m

Washington, D.C. Dulles Intl

週六 21/2

07:30-10:29

Nonstop5h 59m

£178

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

週三 4/2

13:55-21:59

Nonstop5h 04m

Washington, D.C. Reagan-National

週三 11/2

08:00-11:09

Nonstop6h 09m

£178

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週二 10/2

08:30-16:26

Nonstop4h 56m

Washington, D.C. Dulles Intl

週六 14/2

07:05-10:05

Nonstop6h 00m

£178

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週一 5/1

22:14-06:13

Nonstop4h 59m

Washington, D.C. Dulles Intl

週六 10/1

18:04-21:08

Nonstop6h 04m

£178

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

週二 10/2

08:06-20:00

1 stop8h 54m

Washington, D.C. Reagan-National

週二 17/2

17:06-22:18

1 stop8h 12m

£179

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週六 14/3

09:27-17:20

Nonstop4h 53m

Washington, D.C. Dulles Intl

週六 21/3

19:01-22:00

Nonstop5h 59m

£179

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

週三 14/1

15:20-23:10

Nonstop4h 50m

Washington, D.C. Dulles Intl

週四 15/1

07:30-10:29

Nonstop5h 59m

£179

Flights are sorted by cheapest return flights first.

Deals found on 8/12

Showing 1-10 of 46 results
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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 5 December 2025.

To ensure you get the cheapest price possible for a flight from Seattle to Washington, D.C., you should look to book at least 27 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, May is the cheapest month in which you can book a flight from Seattle to Washington, D.C. (average of £86). Flying from Seattle to Washington, D.C. in December is currently the most expensive (average of £161). 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 11 12月 2025.

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 evening could potentially save you up to 29% 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 11 12月 2025.

The most flights from SEA to WAS are scheduled on a Monday (29 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (20 on average).

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 22 daily outbound flights to Washington, D.C. from 0 different airlines.

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

    Alaska Airlines, United Airlines, and Delta can get you from Seattle to Washington, D.C. in just under 4h 50m. Your travel time will be generally consistent. Airlines will cover a distance of 2299 mi. Most flights are nonstop.

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

    Consider Copa Airlines (100%), Avianca (97%) or United Airlines (96%) 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, May is the cheapest month in which you can book a flight from Seattle to Washington, D.C. (average of £86). Flying from Seattle to Washington, D.C. in December is currently the most expensive (average of £161). 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
Woodbridge
Arlington
Alexandria
College Park

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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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