SEA - IAD

C$ 177 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 28/2. 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, 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
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Everything you should know

Cheapest round-trip
C$ 325
Overall average: C$ 461
United Airlines
Tue 24/2Tue 3/3
SEA - IAD • Direct
Cheapest one-way flights
C$ 177
Typical prices: C$ 196-C$ 422
Southwest
Sat 28/2
SEA - IAD • 1 stop
Our travellers' advice
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
United Airlines
Cheapest • from C$ 325 (round-trip)
Hawaiian Airlines
Best reviews • 7.8 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 55% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 23% price drop
April
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.

Tue, 24 Feb - Tue, 3 Mar
United Airlines Logo
8:17 a.m. - 4:19 p.m.
SEA
-
IAD
5h 02mdirect
United Airlines Logo
5:55 p.m. - 8:56 p.m.
IAD
-
SEA
6h 01mdirect
C$ 325United Airlines
Fri, 27 Feb - Sat, 7 Mar
United Airlines Logo
12:25 p.m. - 11:21 p.m.
SEA
-
IAD
7h 56m
1 stop
United Airlines Logo
5:55 p.m. - 8:56 p.m.
IAD
-
SEA
6h 01mdirect
C$ 333United Airlines
Fri, 20 Feb - Mon, 23 Feb
United Airlines Logo
8:17 a.m. - 4:19 p.m.
SEA
-
IAD
5h 02mdirect
United Airlines Logo
1:02 p.m. - 7:03 p.m.
IAD
-
SEA
9h 01m
1 stop
C$ 338United Airlines
Tue, 24 Feb - Tue, 3 Mar
United Airlines Logo
12:43 p.m. - 11:21 p.m.
SEA
-
IAD
7h 38m
1 stop
United Airlines Logo
2:36 p.m. - 9:01 p.m.
IAD
-
SEA
9h 25m
1 stop
C$ 346United Airlines
Tue, 17 Mar - Tue, 24 Mar
Hawaiian Airlines Logo
9:27 a.m. - 5:20 p.m.
SEA
-
IAD
4h 53mdirect
Hawaiian Airlines Logo
7:11 p.m. - 10:02 p.m.
IAD
-
SEA
5h 51mdirect
C$ 351Hawaiian Airlines
Wed, 13 May - Thu, 28 May
Alaska Airlines Logo
3:53 p.m. - 11:59 p.m.
SEA
-
IAD
5h 06mdirect
Alaska Airlines Logo
6:00 a.m. - 8:46 a.m.
IAD
-
SEA
5h 46mdirect
C$ 352Alaska Airlines
Tue, 17 Mar - Tue, 24 Mar
American Airlines Logo
5:30 a.m. - 4:31 p.m.
SEA
-
IAD
8h 01m
1 stop
American Airlines Logo
5:00 a.m. - 11:27 a.m.
IAD
-
SEA
9h 27m
1 stop
C$ 355American Airlines
Fri, 27 Feb - Sat, 7 Mar
United Airlines Logo
8:17 a.m. - 4:19 p.m.
SEA
-
IAD
5h 02mdirect
United Airlines Logo
5:55 p.m. - 8:56 p.m.
IAD
-
SEA
6h 01mdirect
C$ 357United Airlines
Wed, 18 Mar - Sat, 21 Mar
Delta Logo
3:55 p.m. - 11:49 p.m.
SEA
-
IAD
4h 54mdirect
Delta Logo
7:00 a.m. - 10:03 a.m.
IAD
-
SEA
6h 03mdirect
C$ 359Delta
Sat, 21 Feb - Sat, 28 Feb
Delta Logo
3:40 p.m. - 11:34 p.m.
SEA
-
IAD
4h 54mdirect
Delta Logo
7:30 a.m. - 10:29 a.m.
IAD
-
SEA
5h 59mdirect
C$ 364Delta
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, Wednesday is the most expensive day to fly from Seattle to Washington Dulles Airport. For your return ticket, we recommend flying on a Wednesday 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$ 445 (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$ 900 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 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 but there is an average 56% increase in price.
Most popular time to fly and prices are also 14% lower 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 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$ 177 for a one-way ticket and C$ 325 for a round-trip.

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

    Alaska Airlines, Delta, JetBlue, American Airlines, 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 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.

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 2829 reviews
8.0Boarding
7.7Comfort
7.1Entertainment
6.9Food
8.5Crew
Airline reviews

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

2.0 MediocreFrancesca, Jan 2026
JFK - SEA
Read more Hawaiian Airlines reviews

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.

Unfortunately, I was put into the middle seat in the first row of premium seating. Sounds nice right? No! that is the worst seat in the plane. I wish I was in economy rather than be in that seat! There is no seat back pocket, no tray table, no charger. Nothing! so unless you're row mates are willing to let you share their basic amenities any flyer should have, you are stuck. It was the worst experience ever! And the flight attendant forgot to take my drink order. I felt like the forgotten flyer.

Delayed and cancelled flights were hard and very stressful, both ways!

The crew was quite good, they came by often with drinks or to collect trash. But what wasn't nice was the flight was over weigh and several people had to be rebooked. I was questioned whether I should have a seat when I was getting to it. The in-flight entertainment kept buffering and interrupting. And the route took the airplane through high winds which caused us a longer flight

Wasn’t on the flight due to Alaska cancellation…also after all the rerouting, I was going to be on a later flight that left SFO at 7:47pm, which meant an almost 6 hour layover. That same Hawaiian flight was delayed for another 2hours.

I had to cancel the flight because with a 3 hour delay for 'unexpected maintenance' in getting to LAX, I couldn't connect to an overseas flight that I had booked on Scandinavian Air.

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

Information on your arrival and departure airports