SEA - IAD

C$ 176 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 31/3. 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. 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
Travellers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
C$ 295
Overall average: C$ 569
Alaska Airlines
Mon 30/3Sat 4/4
SEA - IAD • Direct
Cheapest one-way flights
C$ 176
Typical prices: C$ 189-C$ 528
Alaska Airlines
Tue 31/3
SEA - IAD • Direct
Advice from real travellers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
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
Alaska Airlines
Cheapest • from C$ 295 (round-trip)
Hawaiian Airlines
Best reviews • 7.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Direct flights
Every day
You can fly direct with Alaska Airlines, Delta, and United Airlines. Average duration is 5h 03m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
When to book
4 weeks
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
February
Cheapest • 28% price drop
December
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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-IAD)

 
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.

Mon, 30 Mar - Sat, 4 Apr
Alaska Airlines Logo
9:40 p.m. - 5:40 a.m.
SEA
-
IAD
5h 00mdirect
Alaska Airlines Logo
7:00 a.m. - 9:53 a.m.
IAD
-
SEA
5h 53mdirect
C$ 295Alaska Airlines
Wed, 22 Apr - Wed, 29 Apr
United Airlines Logo
8:00 a.m. - 4:11 p.m.
SEA
-
IAD
5h 11mdirect
United Airlines Logo
12:55 p.m. - 7:42 p.m.
IAD
-
SEA
9h 47m
1 stop
C$ 297United 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$ 298Alaska Airlines
Thu, 7 May - Sat, 9 May
Delta Logo
4:05 p.m. - 12:15 a.m.
SEA
-
IAD
5h 10mdirect
Delta Logo
3:08 p.m. - 9:56 p.m.
IAD
-
SEA
9h 48m
1 stop
C$ 305Delta
Wed, 1 Apr - Mon, 6 Apr
United Airlines Logo
8:00 a.m. - 4:11 p.m.
SEA
-
IAD
5h 11mdirect
United Airlines Logo
5:41 p.m. - 11:46 p.m.
IAD
-
SEA
9h 05m
1 stop
C$ 309United Airlines
Thu, 23 Apr - Tue, 28 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$ 310Delta
Sun, 12 Apr - Tue, 14 Apr
United Airlines Logo
10:35 p.m. - 11:48 a.m.
SEA
-
IAD
10h 13m
1 stop
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 312United Airlines
Wed, 15 Apr - Mon, 20 Apr
United Airlines Logo
8:00 a.m. - 4:11 p.m.
SEA
-
IAD
5h 11mdirect
United Airlines Logo
5:26 p.m. - 12:34 a.m.
IAD
-
SEA
10h 08m
1 stop
C$ 318United Airlines
Thu, 16 Apr - Wed, 22 Apr
Southwest Logo
1:55 p.m. - 12:20 a.m.
SEA
-
IAD
7h 25m
1 stop
Southwest Logo
4:30 p.m. - 10:30 p.m.
IAD
-
SEA
9h 00m
1 stop
C$ 320Southwest
Wed, 8 Apr - Tue, 14 Apr
United Airlines Logo
2:39 p.m. - 12:32 a.m.
SEA
-
IAD
6h 53m
1 stop
United Airlines Logo
5:55 p.m. - 8:53 p.m.
IAD
-
SEA
5h 58mdirect
C$ 321United Airlines
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 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 February, where tickets cost C$ 412 (return) on average. On the other hand, the most expensive months are January and June, where the average cost of round-trip tickets is C$ 891 and C$ 652 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 55% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Find deals
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.

Read more
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.

Read more

Good to know

Low seasonJanuary
Cheapest flightC$ 176
Best time to beat the crowds but there is an average 56% increase in price.
Most popular time to fly (12% 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. 
Learn how KAYAK collects reviews and tips from users.
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 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$ 176 for a one-way ticket and C$ 295 for a round-trip.

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

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

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

    The Boeing 737 is the aircraft model that flies most regularly on the Seattle to Washington Dulles Airport flight 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$ 529 or less one-way and C$ 322 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 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.
7.8
Hawaiian AirlinesOverall score based on 2838 reviews
8.0Boarding
7.1Entertainment
7.7Comfort
6.9Food
8.5Crew
Airline reviews

The crew were exceptionally nice and accommodating. My wife was tired after the flight from Haneda, Tokyo. They let her sleep and served her dinner later after she woke up, before we landed in PDX.

10.0 ExcellentWing-Kit, Mar 2026
HNL - PDX
Read more Hawaiian Airlines reviews

The crew were exceptionally nice and accommodating. My wife was tired after the flight from Haneda, Tokyo. They let her sleep and served her dinner later after she woke up, before we landed in PDX.

No charging outlets worked. Other than collecting trash attendants didn’t come around. No one could hear flight attendants announcements during the flight. Seat pads were horrible. Sitting on a board for 5 hours. What happened to Hawaiian airlines comfort, hospitality, and extras? Our pilots did an excellent job trying to minimize turbulence and incredible job in landing in windy conditions.

There was no wifi available at any price -- the plane did not have wifi equipment. Movie choices were blah - hits from the past; nothing recent. The food was blah airplane food. They should have had Mai Tai drinks available as per the Hawaiian Airlines magazine, but they had none onboard.

I like that if they asked you to checked in a bag at the gate they give you priority to board

Horrible food and crew. Crew were laughing and talking loud while people were trying to sleep

Yall need to integrate your system with Alaska more efficiently. They booted me off the first flight because of a discrepancy on your end.

The crew at Hawaiian Airlines was fantastic. Kind and hard working. The pilots were great with giving us all the updates to make sure we were informed.

Very good. Nice plane and we sat in economy plus - bigger seats, more room. They served a meal and snacks, and the meal was an apple stuffed pancake that was very good! The snack for us was a hummus sandwich - also very good. The flight attendants were helpful and nice. They have plenty of movies and shows to watch. My only negative -- they changed our flights around and did not adjust the layovers, so we ended up with a very long and unnecessary layover in Honolulu.

I liked the Starlink WiFi but didn't like how they said they were the only airline to offer a free meal and it turns out to be just a standalone sandwich and then charge for snacks to go with it. Rather have the free snacks like Southwest, but have the option to purchase a decent meal for a 5+ hour flight.

Flight scheduled to take off at 5.55pm but it did not take off until 7pm due to some food delivery delay.

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

Information on your arrival and departure airports

Seattle (SEA)
Dulles Intl (IAD)