SEA - IAD

C$ 219 Find Cheap Flights from Seattle to Washington Dulles Airport

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 6/2. 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

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

 
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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Booking Insights
Flight Deals

Cheap Flights from Seattle to Dulles Intl (SEA-IAD)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Dulles Intl 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.

Fri, 10 Oct - Mon, 20 Oct
Delta Logo
4:48 p.m. - 12:40 a.m.SEA-IAD
4h 52mdirect
Delta Logo
7:35 a.m. - 10:28 a.m.IAD-SEA
5h 53mdirect
C$ 356Delta
Find Deal
Wed, 7 Jan - Sun, 11 Jan
United Airlines Logo
5:00 a.m. - 4:35 p.m.SEA-IAD
8h 35m1 stop
United Airlines Logo
5:35 p.m. - 8:37 p.m.IAD-SEA
6h 02mdirect
C$ 364United Airlines
Find Deal
Fri, 3 Oct - Mon, 6 Oct
United Airlines Logo
5:31 p.m. - 5:36 a.m.SEA-IAD
9h 05m1 stop
United Airlines Logo
5:55 p.m. - 8:44 p.m.IAD-SEA
5h 49mdirect
C$ 370United Airlines
Find Deal
Thu, 13 Nov - Sun, 16 Nov
Southwest Logo
5:35 a.m. - 7:00 p.m.SEA-IAD
10h 25m1 stop
Southwest Logo
7:50 p.m. - 12:35 a.m.IAD-SEA
7h 45m1 stop
C$ 372Southwest
Find Deal
Wed, 12 Nov - Sun, 16 Nov
Southwest Logo
6:15 a.m. - 10:10 p.m.SEA-IAD
12h 55m2 stops
Southwest Logo
5:50 p.m. - 12:05 a.m.IAD-SEA
9h 15m1 stop
C$ 374Southwest
Find Deal
Wed, 7 Jan - Wed, 21 Jan
United Airlines Logo
5:00 a.m. - 4:35 p.m.SEA-IAD
8h 35m1 stop
United Airlines Logo
12:35 p.m. - 6:27 p.m.IAD-SEA
8h 52m1 stop
C$ 377United Airlines
Find Deal
Fri, 10 Oct - Fri, 17 Oct
Hawaiian Airlines Logo
4:20 p.m. - 12:23 a.m.SEA-IAD
5h 03mdirect
Hawaiian Airlines Logo
7:41 p.m. - 10:30 p.m.IAD-SEA
5h 49mdirect
C$ 381Hawaiian Airlines
Find Deal
Mon, 5 Jan - Thu, 22 Jan
Alaska Airlines Logo
10:14 p.m. - 6:13 a.m.SEA-IAD
4h 59mdirect
Alaska Airlines Logo
5:51 p.m. - 11:46 p.m.IAD-SEA
8h 55m1 stop
C$ 397Alaska Airlines
Find Deal
Fri, 5 Dec - Sun, 7 Dec
Alaska Airlines Logo
7:59 p.m. - 5:30 p.m.SEA-IAD
18h 31m1 stop
Alaska Airlines Logo
5:37 p.m. - 9:33 a.m.IAD-SEA
18h 56m1 stop
C$ 410Alaska Airlines
Find Deal
Mon, 6 Oct - Thu, 9 Oct
Hawaiian Airlines Logo
4:20 p.m. - 12:23 a.m.SEA-IAD
5h 03mdirect
Hawaiian Airlines Logo
6:25 a.m. - 9:08 a.m.IAD-SEA
5h 43mdirect
C$ 439Hawaiian Airlines
Find Deal

Everything you should know

Our travellers' advice
AI-generated summary based on content written by travel experts and KAYAK users
United's Economy Plus offers more legroom on this route.
Expect traffic delays near Seattle/Tacoma Intl Airport.
Expert advice
Expert advice
+1
+1
Expert advice
Expert advice
+1
Top airlines
Delta
Cheapest • from C$ 356 (round-trip)
Alaska Airlines
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travellers who book at least 4 weeks in advance save around 48% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 15% price drop
December
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest round-trip
C$ 356
Overall average: C$ 466
Delta
Fri 10/10Mon 20/10
SEA - IAD • Direct
Cheapest direct flights
C$ 356
Typical prices: C$ 382-718
Delta
Fri 10/10Sat 25/10
SEA - IAD • Direct
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.!
Expert advice

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

 
Snippets provided in this section are AI-generated based on a summarisation of KAYAK-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airlines
United Airlines

United's Economy Plus offers up to 15 cm more legroom than standard economy seats.


Purchase Priority Boarding to ensure overhead bin space, placing you in Zone 2.

Alaska Airlines

Alaska Airlines' Wine Flies Free program allows free wine case check-in from select airports.


Alaska Airlines' 20-minute baggage guarantee offers compensation if bags delay.

Airports
SEA

Use SEA Spot Saver for expedited security screening. Book online or via the flySEA app for free, available daily from 4 a.m. to 10 p.m.

Read more about SEAby Harriet Baskas
IAD

Take the Silver Line Metro from IAD to D.C. city centre. The ride takes about 50 minutes and is a cost-effective option.

Read more about IADby Stefanie Waldek
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines and IAD

Stefanie Waldek

Stefanie Waldek

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.

Read more
Harriet Baskas

Harriet Baskas

Expert on Alaska Airlines and SEA

Harriet Baskas

Harriet Baskas

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.

Read more
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’s the cheapest day of the week to fly from Seattle to Washington Dulles Airport?

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

If your flying dates are flexible, you should consider flying to Washington Dulles Airport on a Thursday, as we generally find the cheapest rates on that day for this route. On the other hand, Sunday is the most expensive day to fly from Seattle to Washington Dulles Airport. For your return ticket, we recommend flying on a Tuesday and avoiding Saturdays for the best deals.

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

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. Dulles Intl Airport, 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. Dulles Intl Airport is October, where tickets cost C$ 466 (return) on average. On the other hand, the most expensive months are December and June, where the average cost of round-trip tickets is C$ 710 and C$ 660 respectively.

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

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. Dulles Intl Airport, 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. Dulles Intl Airport, you should book around 4 weeks before departure, which saves you about 48% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flightC$ 219
Best time to beat the crowds (14% less expensive on average)
Most popular time to fly (28% more expensive on average)
Flight from Seattle to Washington Dulles 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 AirlinesSEA-IADMay 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 AirlinesSEA-IADMay 2025
Seatac has gnarly traffic right now, took 35min to get from highway exit to the terminal

FAQs for booking Seattle to Washington Dulles Airport flights

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

    In the last 3 days, the lowest price for a flight from Seattle to Washington, D.C. Dulles Intl Airport was C$ 158 for a one-way ticket and C$ 257 for a round-trip.

  • Which airlines offer Wi-Fi service onboard planes from Seattle to Washington Dulles Airport?

    Hawaiian Airlines, Alaska Airlines, Delta, JetBlue, and Lufthansa offer inflight Wi-Fi service on the Seattle to Washington Dulles Airport flight route.

  • Which aircraft models fly most regularly from Seattle to Washington Dulles Airport?

    The Boeing 737 MAX 9 is the aircraft model that flies most regularly on the Seattle to Washington Dulles Airport flight route.

  • Which airline alliances offer flights from Seattle to Washington Dulles Airport?

    oneworld, Star Alliance, and SkyTeam are the airline alliances operating flights between Seattle and Washington Dulles Airport, with Star Alliance being the most commonly used for this route.

  • On which days can I fly direct from Seattle to Washington Dulles Airport?

    There are direct flights from Seattle to Washington Dulles Airport on a daily basis.

  • Which is the best airline for flights from Seattle to Washington, D.C., Alaska Airlines or Hawaiian Airlines?

    The two airlines most popular with KAYAK users for flights from Seattle to Washington, D.C. are Alaska Airlines and Hawaiian Airlines. With an average price for the route of C$ 391 and an overall rating of 8.0, Alaska Airlines is the most popular choice. Hawaiian Airlines is also a great choice for the route, with an average price of C$ 363 and an overall rating of 7.8.

  • How does KAYAK find such low prices on flights from Seattle to Washington Dulles Airport?

    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 Dulles Airport.

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

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

  • What is the Hacker Fare option on flights from Seattle to Washington Dulles Airport?

    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 Dulles Airport 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 Dulles Airport?

    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 Dulles Airport 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. Dulles Intl Airport

  • Looking for a cheap flight? 25% of our users found flights on this route for C$ 1,058 or less one-way and C$ 363 or less round-trip.

Prefer to fly direct from Seattle to Washington Dulles Airport?

 
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. Dulles Intl.
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport, which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Washington, D.C. Dulles 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

Direct returns

Washington, D.C. Dulles Intl 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

Reviews of the top airlines flying from Seattle to Washington, D.C.

 
See real verified KAYAK customer reviews for airlines flying from Seattle to Washington, D.C.. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Seattle to Washington, D.C.? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 10000 reviews
7.8Comfort
8.1Boarding
7.0Entertainment
7.1Food
8.5Crew
Airline reviews

Flight was delayed as it always is with Alaska airlines. Particularly to smaller airports. No AC on the plane so it was miserably hot.

4.0 OkayKristina, Sep 2025SEA - GTF
Read more Alaska Airlines reviews

Flight was delayed as it always is with Alaska airlines. Particularly to smaller airports. No AC on the plane so it was miserably hot.

Slow boarding and the flight crew hit me with the food cart

It was very nice flight going to Seattle and coming back to Omaha. Even got in early. Very easy to check in using the Alaska Airlines App. Thank you.

They offer the only direct flight from Seattle to Pittsburgh.

Seattle airport is a mess. New bag tag system has potential, but you need more signage to guide passengers through the process as to where to go next. Told to go in one direction and then met with a very rude agent when we did. He blamed his attitude on all the folks flying over labor day that were paying his salary. Gate area for D3 is a mess compared to the North terminal. Overall Alaska is number 1 in my book.

After we boarded there was quite a long time before we actually took off, and there were no announcements from crew about why we were delayed. Later when they did make announcements they were largely inaudible. There was no food (other than for purchase) on the flight and no entertainment. Thats not a complaint, just explaining my ratings in those categories. The flight was smooth. Baggage claim was rapid.

The airline staff was great! The best safety review ive ever had!

Agent boarding us in San Diego lectured me on showing up on time for the flight, and said that if I had been three minutes later, he would have denied myself and my wife boarding. Our trusted traveler numbers were not in the system, even though I entered them when I bought the tickets. Our food orders were not in the system, even though I entered them prior to the flight. My wife requires a wheelchair, and that was delayed on both flights.

Why was I charged for a glass of wine on one flight and not on another? Why no movie or TVs? It was a long flight.

I liked that it didn't take 10 hours to drive here. Super short trip!

They we able to seat my companion and I next to each other. Plane’s temperature was very cool. Willl be more prepared on return trip.

All was good and they were able to seat my travel companion next to me. Thank you.

Like the ample leg room. May as well not bother with snacks if it's only a two ounce bag of pretzels. Didn't use the entertainment option. Was there one?

What an amazing flight. I haven’t experienced this level of service in a flight in years. This will be the only way to fly to Hawaii for me in the future.

Kayak sold me a ticket after check in time. Could not check in. Could not get on flight.

Love you guys are so friendly and kind and wonderful

Agents talk too fast over intercom. I know it’s memorized and we’ve all heard it before. Just slow down a little. Stop charging for checked bags. I was pleased to get my bags promptly at each end of my flight.

Everything was great except having to check in at Alaska. That was a surprise and took extra time and effort. Should have been explained somewhere maybe on the HA electronic ticket.

It was clean and the crew was great. I wish the chairs could recline just a little more and you would provide small pillows for people with bad backs. My back is fused and a little support would be great.

I accidentally made this purchase and they wouldn’t refund me even though I called immediately to cancel it.

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

Information on your arrival and departure airports

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