SEA - IAD

C$ 191 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 20/9. 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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Flights 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.

Tue, 26 Aug - Tue, 16 Sep
Hawaiian Airlines Logo
4:20 p.m. - 12:20 a.m.SEA-IAD
5h 00mdirect
Hawaiian Airlines Logo
6:09 p.m. - 8:56 p.m.IAD-SEA
5h 47mdirect
C$ 354Hawaiian Airlines
Find Deal
Sat, 30 Aug - Sat, 6 Sep
Delta Logo
9:55 p.m. - 5:55 a.m.SEA-IAD
5h 00mdirect
Delta Logo
7:35 a.m. - 10:20 a.m.IAD-SEA
5h 45mdirect
C$ 355Delta
Find Deal
Wed, 17 Sep - Sun, 21 Sep
Hawaiian Airlines Logo
11:30 p.m. - 7:33 a.m.SEA-IAD
5h 03mdirect
Hawaiian Airlines Logo
9:00 a.m. - 11:43 a.m.IAD-SEA
5h 43mdirect
C$ 362Hawaiian Airlines
Find Deal
Tue, 26 Aug - Tue, 2 Sep
United Airlines Logo
1:55 p.m. - 12:32 a.m.SEA-IAD
7h 37m1 stop
United Airlines Logo
1:05 p.m. - 3:51 p.m.IAD-SEA
5h 46mdirect
C$ 367United Airlines
Find Deal
Wed, 1 Oct - Tue, 7 Oct
Alaska Airlines Logo
11:30 p.m. - 7:33 a.m.SEA-IAD
5h 03mdirect
Alaska Airlines Logo
6:25 a.m. - 9:08 a.m.IAD-SEA
5h 43mdirect
C$ 380Alaska Airlines
Find Deal
Tue, 26 Aug - Sat, 30 Aug
Alaska Airlines Logo
11:30 p.m. - 7:32 a.m.SEA-IAD
5h 02mdirect
Alaska Airlines Logo
6:09 p.m. - 8:51 p.m.IAD-SEA
5h 42mdirect
C$ 381Alaska Airlines
Find Deal
Wed, 24 Sep - Wed, 1 Oct
Alaska Airlines Logo
8:59 p.m. - 4:52 p.m.SEA-IAD
16h 53m1 stop
Alaska Airlines Logo
6:09 p.m. - 8:56 p.m.IAD-SEA
5h 47mdirect
C$ 395Alaska Airlines
Find Deal
Wed, 27 Aug - Sat, 6 Sep
Southwest Logo
7:00 a.m. - 10:05 p.m.SEA-IAD
12h 05m2 stops
Southwest Logo
5:05 p.m. - 9:50 p.m.IAD-SEA
7h 45m1 stop
C$ 415Southwest
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Thu, 28 Aug - Sun, 31 Aug
United Airlines Logo
10:55 p.m. - 6:58 a.m.SEA-IAD
5h 03mdirect
United Airlines Logo
7:00 a.m. - 1:30 p.m.IAD-SEA
9h 30m1 stop
C$ 422United Airlines
Find Deal
Sat, 15 Nov - Wed, 19 Nov
Southwest Logo
10:15 a.m. - 10:15 p.m.SEA-IAD
9h 00m1 stop
Southwest Logo
7:40 a.m. - 10:55 p.m.IAD-SEA
18h 15m2 stops
C$ 424Southwest
Find Deal
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 Saturday, 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 September, where tickets cost C$ 464 (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$ 706 and C$ 656 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 45% 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$ 191
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$ 139 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, JetBlue, Delta, and American Airlines 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.

  • 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$ 389 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

ANA,Air Tahiti Nui,Alaska Airlines, +14 more

ANA,Air Tahiti Nui, +15 more

Tuesday

ANA,Air Tahiti Nui,Alaska Airlines, +15 more

ANA,Air Tahiti Nui, +16 more

Wednesday

ANA,Air Tahiti Nui,Alaska Airlines, +14 more

ANA,Air Tahiti Nui, +15 more

Thursday

ANA,Air Tahiti Nui,Alaska Airlines, +15 more

ANA,Air Tahiti Nui, +16 more

Friday

ANA,Air Tahiti Nui,Alaska Airlines, +15 more

ANA,Air Tahiti Nui, +16 more

Saturday

ANA,Air Tahiti Nui,Alaska Airlines, +15 more

ANA,Air Tahiti Nui, +16 more

Sunday

ANA,Air Tahiti Nui,Alaska Airlines, +15 more

ANA,Air Tahiti Nui, +16 more

See more nonstop flights

Direct returns

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

Monday

Air Tahiti Nui,Alaska Airlines,American Airlines, +15 more

Air Tahiti Nui,Alaska Airlines, +16 more

Tuesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +14 more

Air Tahiti Nui,Alaska Airlines, +15 more

Wednesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +15 more

Air Tahiti Nui,Alaska Airlines, +16 more

Thursday

Air Tahiti Nui,Alaska Airlines,American Airlines, +15 more

Air Tahiti Nui,Alaska Airlines, +16 more

Friday

Air Tahiti Nui,Alaska Airlines,American Airlines, +14 more

Air Tahiti Nui,Alaska Airlines, +15 more

Saturday

Air Tahiti Nui,Alaska Airlines,American Airlines, +15 more

Air Tahiti Nui,Alaska Airlines, +16 more

Sunday

Air Tahiti Nui,Alaska Airlines,American Airlines, +15 more

Air Tahiti Nui,Alaska Airlines, +16 more

See more nonstop flights

Reviews of the top airline 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
7.1Food
8.1Boarding
7.8Comfort
8.5Crew
7.1Entertainment
Airline reviews

Crew was very friendly. Our bags showed up at the carousel within 20 minutes of arrival.

8.0 ExcellentAnonymous, Jul 2025SEA - MSY
Read more Alaska Airlines reviews

Crew was very friendly. Our bags showed up at the carousel within 20 minutes of arrival.

Flight was delayed and hour due to tire issue. First flight of the day, this issue should have been discovered prior to boarding.

Both legs of the trip were delayed about an hour. Planes were new, liked the WiFi availability and entertainment available. Crew was very good. People were happy and helpful. Liked the pilots - they provided updates throughout the flights. Snacks were underwhelming. Drinks were good! Like the smaller sodas and they actually came through the cabin 2x which was great. In Seattle airport the construction caused much confusion for Alaska. Process of printing own tags, etc was chaotic for people who didn’t check in online prior to arrival which in turn caused issues for those who did. Plus airport gates were too small for the number of people flying.

We did have to wait an hour for the runway to be cleared but other than that it was fine.

My seat row didn’t have tray tables which made it pretty difficult to get comfortable on a four hour flight. Good experience outside of that, though.

There was no sitting place in Sea-Tac airport. Even airline didn’t provide any food or dinner. I will never take this airline in my future travel.

Crew was very rude and uncaring. When someone tried to place their bag in overhead bin and they asked for help, crew told them they could not assist. Crew member then told the customer if they couldn’t place into overhead bin on their own, they should have checked in bag. When other customer helped to place the bag in the overhead bin, they were given evil look by crew member and told to hurry back to their uncomfortable middle seat. This was despite the fact that the plane did not leave until 30 minutes later. The flight was ~80% full; when final people boarded, they were forced into middle seats with no room for comfort. There were a handful of emergency row seats unoccupied. When asked if any of the emergency row seats may be used, the crew said that they would cost extra. Normally if a flight is completely boarded and there are open seats, the crew at least gives thought to asking someone if they want to re-locate to the more comfortable seat, especially on a long flight.

Great flight, no bumps to speak of, pleasant crew, good inflight entertainment choices

I am always uncomfortable about the boarding process. I think every airlines has their own procedures for boarding but all of their procedures are inconvenient because it takes too much time to board. If you board people from back seat to front, I think you can reduce the time to boarding.

Our original fluffy was cancelled. Our substitute flight didn't fly. We lost out on our hotel and car rental. Had to fly out the next morning. Alaska didn't give us any meaningful information. The first flight was scheduled to leave at 4pm and the substitute flight at 9pm. We left the airport at midnight for a hotel. No weather. Beyond disappointed.

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

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