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Cheap flights from Seattle to Washington, D.C. from £106

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 17/3. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — WAS
13 Dec — 20 Dec1
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 61 days in advance, depart on a Tuesday or Monday and return on a Tuesday

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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 13 November 2025.

Fri 12/1222:11SEA - IAD
Nonstop4h 55mAlaska Airlines
Sun 14/1207:34IAD - SEA
Nonstop6h 01mAlaska Airlines
Deal found 12/11£181
Sun 14/1207:25SEA - DCA
Nonstop5h 02mDelta
Tue 16/1216:55DCA - SEA
Nonstop5h 53mDelta
Deal found 11/11£182
Mon 8/1215:30SEA - IAD
Nonstop4h 57mDelta
Wed 10/1207:15IAD - SEA
Nonstop5h 57mDelta
Deal found 12/11£182
Thu 11/1208:10SEA - IAD
Nonstop5h 08mUnited Airlines
Sun 14/1217:55IAD - SEA
Nonstop5h 59mUnited Airlines
Deal found 12/11£183
Thu 11/1215:30SEA - IAD
Nonstop4h 57mDelta
Sun 14/1207:15IAD - SEA
Nonstop5h 57mDelta
Deal found 11/11£185
Thu 11/1222:11SEA - IAD
Nonstop4h 55mAlaska Airlines
Mon 15/1207:34IAD - SEA
Nonstop6h 01mAlaska Airlines
Deal found 11/11£186
Mon 8/1222:11SEA - IAD
Nonstop4h 55mAlaska Airlines
Wed 10/1217:37IAD - SEA
1 stop9h 35mAlaska Airlines
Deal found 12/11£189
Mon 8/1207:25SEA - DCA
Nonstop5h 02mDelta
Fri 12/1218:21DCA - SEA
1 stop8h 37mDelta
Deal found 12/11£190
Sun 14/1208:10SEA - IAD
Nonstop5h 08mUnited Airlines
Wed 17/1217:15IAD - SEA
1 stop8h 13mUnited Airlines
Deal found 12/11£190
Wed 3/1223:55SEA - DCA
1 stop8h 14mDelta
Sun 7/1216:55DCA - SEA
Nonstop5h 53mDelta
Deal found 10/11£193
Mon 8/1221:39SEA - DCA
1 stop17h 20mAlaska Airlines
Wed 10/1208:00DCA - SEA
Nonstop6h 11mAlaska Airlines
Deal found 12/11£193
Thu 11/1209:05SEA - IAD
1 stop8h 34mUnited Airlines
Fri 12/1206:00IAD - SEA
1 stop8h 16mUnited Airlines
Deal found 10/11£193

Cheap 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 13 November 2025.

Round-trip from

£180

One-way from

£106

Popular in

December

Cheapest in

August

Average price

£371

Good one-way deal

£338 or less
Alaska Airlines
  • Alaska Airlines
  • 14/1-19/1
  • 2 total stops
  • 17h 18m total
  • Seattle to Washington, D.C.
Search Deals
Alaska Airlines
  • Alaska Airlines
  • 17/3
  • Nonstop
  • 5h 03m total
  • Seattle to Washington, D.C.
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (£46 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (£6 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 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 13 November 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 - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 11/12

08:40-16:36

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sun 14/12

07:34-10:35

Nonstop6h 01m

£181

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Tue 3/3

07:20-15:20

Nonstop5h 00m

Washington, D.C. Reagan-National

Wed 4/3

16:44-19:43

Nonstop5h 59m

£182

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Mon 8/12

07:25-15:27

Nonstop5h 02m

Washington, D.C. Reagan-National

Wed 10/12

16:55-19:48

Nonstop5h 53m

£182

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Sun 14/12

07:25-15:27

Nonstop5h 02m

Washington, D.C. Reagan-National

Mon 15/12

16:55-19:48

Nonstop5h 53m

£182

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Sun 14/12

07:25-15:27

Nonstop5h 02m

Washington, D.C. Reagan-National

Tue 16/12

16:55-19:48

Nonstop5h 53m

£182

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Mon 12/1

07:20-15:20

Nonstop5h 00m

Washington, D.C. Reagan-National

Fri 16/1

16:55-19:54

Nonstop5h 59m

£182

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Fri 13/2

13:56-21:59

Nonstop5h 03m

Washington, D.C. Reagan-National

Mon 16/2

17:00-20:11

Nonstop6h 11m

£190

SeattleWashington, D.C.

SEA - DCA

SEADCA

Seattle/Tacoma Intl

Mon 8/12

07:25-15:27

Nonstop5h 02m

Washington, D.C. Reagan-National

Fri 12/12

06:02-10:40

1 stop7h 38m

£190

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 16/12

15:30-23:27

Nonstop4h 57m

Washington, D.C. Dulles Intl

Wed 17/12

17:59-23:58

1 stop8h 59m

£190

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 2/2

07:00-17:35

1 stop7h 35m

Washington, D.C. Dulles Intl

Thu 12/2

13:02-19:03

1 stop9h 01m

£196

Flights are sorted by cheapest return flights first.

Deals found on 11/11

Showing 1-10 of 45 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 7 November 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 61 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 £88). Flying from Seattle to Washington, D.C. in December is currently the most expensive (average of £164). 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 13 November 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 13 November 2025.

The most flights from SEA to WAS are scheduled on a Monday (30 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (18 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 25 daily outbound flights to Washington, D.C. from 0 different airlines.

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

    Delta, United Airlines, and Alaska Airlines can get you from Seattle to Washington, D.C. in just under 5h 02m. Your travel time will be generally consistent. Airlines will cover a distance of 2321 mi. Most flights are nonstop.

  • What are the cheapest airlines to fly from Seattle to Washington, D.C. one-way?

    The cheapet airlines for a one-way flight from Seattle to Washington, D.C. are Delta (£106), Alaska Airlines (£110), and Southwest (£125).

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

    Consider Copa Airlines (100%), Avianca (100%) or Iberia (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, May is the cheapest month in which you can book a flight from Seattle to Washington, D.C. (average of £88). Flying from Seattle to Washington, D.C. in December is currently the most expensive (average of £164). 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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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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