SEA - WAS

C$ 177 Find Cheap Flights from Seattle to Washington, D.C.

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Washington, D.C. departing on 11/5. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Washington, D.C.

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Washington, D.C., as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Washington, D.C., as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
C$ 299
Overall average: C$ 476
United Airlines
Sat 18/4Tue 21/4
SEA - IAD • 1 stop
Cheapest direct flights
C$ 300
Typical prices: C$ 398-C$ 631
Alaska Airlines
Tue 28/4Wed 29/4
SEA - IAD • Direct
Advice from real travellers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
Alaska's 20-minute baggage guarantee offers rewards.
Expect traffic delays near Seattle/Tacoma Intl Airport.
Expert advice
Expert advice
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Expert advice
Expert advice
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Direct flights
You can fly direct with Alaska Airlines, Delta, and United Airlines. Average duration is 5h 03m
Direct flights
Direct flights
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Direct flights
Direct flights
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Top routes
Cheapest • 34% average savings
Most popular
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 4 weeks in advance save around 55% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 20% price drop
Most popular
Good to know
Good to know
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Good to know
Good to know
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Start a new search
KAYAK searches hundreds of sites at once to find you the best travel deals.
We hope you love your trip to Washington, D.C.!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Seattle to Washington, D.C. (SEA-WAS)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Washington, D.C. that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to Washington, D.C.

Sat, 18 Apr - Tue, 21 Apr
United Airlines Logo
10:48 a.m. - 9:04 p.m.
SEA
-
IAD
7h 16m
1 stop
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 299United Airlines
Tue, 28 Apr - Wed, 29 Apr
Alaska Airlines Logo
3:55 p.m. - 12:09 a.m.
SEA
-
IAD
5h 14mdirect
Alaska Airlines Logo
7:10 a.m. - 9:58 a.m.
IAD
-
SEA
5h 48mdirect
C$ 300Alaska Airlines
Wed, 29 Apr - Mon, 4 May
Southwest Logo
6:00 a.m. - 6:40 p.m.
SEA
-
DCA
9h 40m
2 stops
Southwest Logo
7:45 p.m. - 12:05 a.m.
DCA
-
SEA
7h 20m
1 stop
C$ 307Southwest
Wed, 6 May - Fri, 8 May
Southwest Logo
9:20 a.m. - 11:40 p.m.
SEA
-
IAD
11h 20m
1 stop
Southwest Logo
5:55 p.m. - 11:30 p.m.
IAD
-
SEA
8h 35m
1 stop
C$ 307Southwest
Sat, 18 Apr - Tue, 21 Apr
United Airlines Logo
7:00 a.m. - 5:28 p.m.
SEA
-
IAD
7h 28m
1 stop
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 311United Airlines
Mon, 27 Apr - Tue, 5 May
United Airlines Logo
8:00 a.m. - 4:11 p.m.
SEA
-
IAD
5h 11mdirect
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 313United Airlines
Wed, 29 Apr - Wed, 6 May
Southwest Logo
6:50 a.m. - 8:50 p.m.
SEA
-
DCA
11h 00m
2 stops
Southwest Logo
3:40 p.m. - 10:30 p.m.
DCA
-
SEA
9h 50m
2 stops
C$ 314Southwest
Wed, 22 Apr - Wed, 29 Apr
United Airlines Logo
7:00 a.m. - 5:28 p.m.
SEA
-
IAD
7h 28m
1 stop
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 314United Airlines
Fri, 1 May - Sat, 2 May
Delta Logo
7:30 a.m. - 3:27 p.m.
SEA
-
DCA
4h 57mdirect
Delta Logo
4:39 p.m. - 7:30 p.m.
DCA
-
SEA
5h 51mdirect
C$ 321Delta
Mon, 13 Apr - Wed, 22 Apr
Delta Logo
3:59 p.m. - 11:55 p.m.
SEA
-
IAD
4h 56mdirect
Delta Logo
7:00 a.m. - 9:54 a.m.
IAD
-
SEA
5h 54mdirect
C$ 321Delta
Booking Insights

KAYAK's insights & trends for Seattle to Washington, D.C. flights

Get data-powered insights and trends into flights from Seattle to Washington, D.C. to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest Seattle to Washington, D.C. flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest return flight from Seattle to Washington, D.C. costs C$ 380 on the route between Seattle (SEA) and Washington, D.C. Reagan-National Airport (DCA). Over the past month, flights between Seattle (SEA) and Baltimore (BWI) were, on average, 34% cheaper than other Seattle-Washington, D.C. routes. This is also the most popular route.

What’s the cheapest day of the week to fly from Seattle to Washington, D.C.?

The average price of all round-trip flights from Seattle to Washington, D.C. clicked on KAYAK for each day over the last 12 months.

When flying from Seattle to Washington, D.C., you should consider leaving on a Thursday and avoid Mondays if you are looking for the best rates. For your return to Seattle, you’ll find the best rates on Thursdays and the most expensive ones on Wednesdays.

What is the cheapest month to fly from Seattle to Washington, D.C.?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to Washington, D.C., removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Seattle to Washington, D.C. is January, where tickets cost C$ 421 (return) on average. On the other hand, the most expensive months are June and March, where the average cost of round-trip tickets is C$ 600 and C$ 587 respectively.

Can I save money by flying with a layover from Seattle to Washington, D.C.?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at C$ 346 on average.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Seattle to Washington, D.C., removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Seattle to Washington, D.C., you should book around 4 weeks before departure, which saves you about 55% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Expert advice

Expert advice for your flight from Seattle to Washington, D.C.

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Harriet Baskas

Harriet Baskas

Expert on Alaska Airlines and SEA

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Stefanie Waldek

Stefanie Waldek

Expert on United Airlines and IAD

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Good to know

Low seasonJanuary
Cheapest flightC$ 177
Best time to beat the crowds (20% less expensive on average)
Most popular time to fly and prices are also 3% lower on average.
Flight from Seattle to Reagan Washington National Airport

When to book flights from Seattle to Washington, D.C.

Are your dates flexible? Find out the best times to travel from Seattle to Washington, D.C. based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Flights from Seattle to Washington, D.C.: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Seattle to Washington, D.C. 
SuzetteFlew with Alaska Airlines
SEA
-
IAD
May 2025
Take a shower before arriving at airport and don't wear perfume at all! Pack bags tight, so boarding is smooth and quick.
DanielFlew with Alaska Airlines
SEA
-
IAD
May 2025
Seatac has gnarly traffic right now, took 35min to get from highway exit to the terminal

FAQs for booking flights from Seattle to Washington, D.C.

  • What is the cheapest flight from Seattle to Washington, D.C.?

    In the last 3 days, the lowest price for a flight from Seattle to Washington, D.C. was C$ 177 for a one-way ticket and C$ 299 for a round-trip.

  • Which airports will I be using when flying from Seattle to Washington, D.C.?

    On your way to Washington, D.C., you’ll fly out from Seattle/Tacoma Intl. You’ll be landing in one of Washington, D.C.’s 2 airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl.

  • Which airlines offer Wi-Fi service onboard planes from Seattle to Washington, D.C.?

    Alaska Airlines, and Delta offer inflight Wi-Fi service on the Seattle to Washington, D.C. flight route.

  • Which aircraft models fly most regularly from Seattle to Washington, D.C.?

    The Boeing 737-800 Passenger/BBJ2 (winglets) is the aircraft model that flies most regularly on the Seattle to Washington, D.C. flight route.

  • On which days can I fly direct from Seattle to Washington, D.C.?

    There are direct flights from Seattle to Washington, D.C. on a daily basis.

  • How does KAYAK find such low prices on flights from Seattle to Washington, D.C.?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to Washington, D.C..

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to Washington, D.C.?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Washington, D.C. from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to Washington, D.C.?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Washington, D.C. with an airline and back to Seattle with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to Washington, D.C.?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Washington, D.C. from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Seattle to Washington, D.C.

  • Looking for a cheap flight? 25% of our users found flights on this route for C$ 533 or less one-way and C$ 850 or less round-trip.

Prefer to fly direct from Seattle to Washington, D.C.?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Seattle/Tacoma Intl to Washington, D.C..
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Washington, D.C., which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Washington, D.C.

Monday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Tuesday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Wednesday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Thursday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Friday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Saturday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Sunday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

See more nonstop flights

Direct returns

Washington, D.C. to Seattle/Tacoma Intl

Monday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Tuesday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Wednesday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Thursday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Friday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Saturday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

Sunday

Alaska Airlines,Delta,United Airlines

Alaska Airlines,Delta, +1 more

See more nonstop flights

Everything you need to know for your flight from Seattle to Washington, D.C.

Information on your arrival and departure airports