SEA - IAD

C$ 179 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 24/5. 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

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

Save 27% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Free to useThere are no hidden charges or fees.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Cheap Flight Deals 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.

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

KAYAK's recommended round-trip deals from the most popular airlines that fly from Seattle to Washington, D.C..
Discover the best prices for you by selecting your travel dates on KAYAK.
Choose your dates
Delta Logo
9:50 p.m. - 5:52 a.m.SEA-IAD
5h 02mdirect
Delta Logo
7:40 a.m. - 10:28 a.m.IAD-SEA
5h 48mdirect
C$ 356Delta
Find Deal
mar., 3 jun. - mar., 10 jun.
Hawaiian Airlines Logo
9:18 a.m. - 5:15 p.m.SEA-IAD
4h 57mdirect
Hawaiian Airlines Logo
7:15 a.m. - 1:44 p.m.IAD-SEA
9h 29m1 stop
C$ 368Hawaiian Airlines
Find Deal
mar., 3 jun. - mar., 10 jun.
 Logo
6:52 p.m. - 6:31 a.m.SEA-IAD
8h 39m1 stop
 Logo
6:30 a.m. - 9:10 a.m.IAD-SEA
5h 40mdirect
C$ 375
Find Deal
vie., 16 may. - mar., 20 may.
Alaska Airlines Logo
4:00 p.m. - 11:58 p.m.SEA-IAD
4h 58mdirect
Alaska Airlines Logo
6:30 a.m. - 9:10 a.m.IAD-SEA
5h 40mdirect
C$ 377Alaska Airlines
Find Deal
mar., 13 may. - mar., 20 may.
 Logo
6:52 p.m. - 6:31 a.m.SEA-IAD
8h 39m1 stop
 Logo
7:15 a.m. - 1:44 p.m.IAD-SEA
9h 29m1 stop
C$ 382
Find Deal
vie., 16 may. - mar., 20 may.
Alaska Airlines Logo
8:08 a.m. - 5:55 a.m.SEA-IAD
18h 47m1 stop
Alaska Airlines Logo
7:59 p.m. - 9:09 a.m.IAD-SEA
16h 10m1 stop
C$ 384Alaska Airlines
Find Deal
mié., 21 may. - mar., 27 may.
Sun Country Air Logo
11:59 p.m. - 12:31 p.m.SEA-IAD
9h 32m1 stop
Sun Country Air Logo
12:40 p.m. - 10:50 p.m.IAD-SEA
13h 10m1 stop
C$ 464Sun Country Air
Find Deal
jue., 7 ago. - dom., 10 ago.
Sun Country Air Logo
11:59 p.m. - 12:25 p.m.SEA-IAD
9h 26m1 stop
Sun Country Air Logo
7:45 a.m. - 8:02 a.m.IAD-SEA
27h 17m1 stop
C$ 471Sun Country Air
Find Deal
jue., 12 jun. - dom., 15 jun.
United Airlines Logo
12:55 p.m. - 9:03 p.m.SEA-IAD
5h 08mdirect
United Airlines Logo
10:09 p.m. - 12:59 a.m.IAD-SEA
5h 50mdirect
C$ 519United Airlines
Find Deal
sáb., 17 may. - jue., 22 may.
United Airlines Logo
5:15 a.m. - 3:36 p.m.SEA-IAD
7h 21m1 stop
United Airlines Logo
8:30 a.m. - 3:58 p.m.IAD-SEA
10h 28m1 stop
C$ 522United Airlines
Find Deal
mar., 13 may. - mar., 20 may.

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

 
Snippets provided in this section are AI-generated based on a summarization 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 specific 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
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.

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.

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
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
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

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 Wednesday, 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 Thursday 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 February, where tickets cost C$ 476 (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$ 715 and C$ 673 respectively.

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

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.
No, with an average price for the route of C$ 892, prices are generally cheapest when you fly direct.

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. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.

Good to know

Low season

February

High season

May

Cheapest flight

C$ 179
Best time to beat the crowds (16% less expensive on average)
Most popular time to fly (2% 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. 
StacieFlew with Alaska AirlinesSEA-IADJun 2024
Watch your dates that you book. Don’t forget about the Alaska cruises. Sunday everyone flying home after cruise. Flights booked!
Verified travelerFlew with Alaska AirlinesSEA-IADMay 2024
Fly a larger carrier with the usual amenities: Delta, United, American.

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$ 129 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?

    Alaska Airlines, Hawaiian Airlines, JetBlue, Delta, and KLM 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 United Airlines?

    The two airlines most popular with KAYAK users for flights from Seattle to Washington, D.C. are Alaska Airlines and United Airlines. With an average price for the route of C$ 446 and an overall rating of 8.0, Alaska Airlines is the most popular choice. United Airlines is also a great choice for the route, with an average price of C$ 1,188 and an overall rating of 7.4.

  • 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.

See more FAQs

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$ 331 or less one-way and C$ 397 or less round-trip.

Prefer to fly direct from Seattle to Washington Dulles Airport?

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, +14 more

Air Tahiti Nui,Alaska Airlines, +15 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
See more nonstop flights

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 9918 reviews
8.2Boarding
8.5Crew
7.9Comfort
7.1Food
7.1Entertainment
Airline reviews

Awful. We got the last seats and they don't recline. We've been on this horrible journey since 6am and won't get to our destination almost a full day later. Oh and no food, either. Never again.

2.0 MediocreDeb, Apr 2025SEA - HNL
Read more Alaska Airlines reviews

Awful. We got the last seats and they don't recline. We've been on this horrible journey since 6am and won't get to our destination almost a full day later. Oh and no food, either. Never again.

The flight was delayed by 3 hours and 30 minutes without any explanation.

An uneventful flight is a good experience although one of the pilots gauges wasn’t working right so we had a half hour delay—no one can foresee that.

Plane was delayed and got me in past bedtime. But more importantly, my tsa precheck number wasn’t on my ticket so had to deal with the general line. Oh well, guess the delay helped that situation.

It was as good as flying can be, which is still very uncomfortable. Clean new aircraft, great crew.

Everything was good. The flight attendants were great. I was disappointed that there wasn’t any screens on the back of the seats to watch movies, tv, etc. I only had my phone to watch movies on.

Flight delayed due to engine issue. For 3+ hours still not on flight

Could have had more of a beverage selection than water and apple juice.

They only had one flight to my destination for the entire day. Six hour layover. Coming from their sister airline we didn't have any boarding grouping on our boarding tickets. Had to ask where we were within the grouping.

Flight was over an hour late, and we got notified every 15 minutes, beginning right at boarding, that it would only be 15 more minutes until we finally left about 75 minutes late. Of course, no compensation was offered.

Mostly the experience was good except for the flight changes made by UA which meant longer layover in DC

Terrible. First of all we were delayed 4 3/4 hours departing Honolulu. As we had to leave our condo and the rental car had to be returned we had to go to the airport. Even though we had a business class boarding pass to Washington, since we did not have business class to Montreal we could not access the lounge without paying a $59 fee each. This does not make sense to us. Since we could not meet our original connection United booked us to Montreal via New York LaGuardia on Air Canada. In Washington a further delay got us into LaGuardia too late to make our connection to Montreal so we were booked on another Air Canada flight 3 hours later. We were originally scheduled to arrive in Montreal at 10:40 and arrived at 19:55. A totally exhausting day, United did not offer a meal voucher or any type of compensation. Air Canada did give us a digital meal voucher. The food in United business class is poor among all meals offered. The pods look nice but are not that confortable. Overall would not fly on United again.

Change cabin crew assisting business class. Not taking care, ignoring requests and calls. Never had such an experience in business class.

United left one of our bags back in SFO but that’s not my real complaint. The complaint is how it all went down. So we checked in the day before online and were told we could use the quick drop for luggage. So the next day I used baggage quick drop curbside at SFO. The agent mistakenly didn't tag my bag as he put my bag on the conveyor belt untagged. We immediately alerted him he had not tagged the bag. I walked with him to the baggage service office to find my bag and tag it. We waited outside the office for 10 mins. He came out and said everything was ok and the bag was going to be tagged and on my flight. We received a text that one of our bags was on the flight but the other was not. I alerted my first class flight attendant immediately upon boarding the flight. She was helpful and said she’d get it sorted out right away. She called over the gate agent. The gate agent used my bag number and looked over information on her device. She said my bag was on the flight. The flight attendant was standing with her, looking at the device, and also said “yep it’s on the flight”. During the flight the flight attendant made reference to how reassuring it must feel knowing the bag was on the flight. Upon arriving to IAD we received a text that my bag was not on my flight. The text said my bag would arrive to my final destination LIS 24 hrs late. I understand that mistakes happen. I was totally ok with my bag mistakenly not getting tagged at the quick drop. I was fine with walking down to baggage services to tag my bag. But, what I am not ok with is that the United staff said they fixed the mistake two different times, assuring me twice that my bag would be/was on the plane…and it wasn’t. I expected better attention by the employees, for them to do what they said they were going to do. We also spent extra money to upgrade our seats to first class, including the entire return leg from Lisbon to San Francisco because we wanted a smoother and more relaxing travel experience. Our money was not well spent. We will not be using United for travel going forward.

The flight was delayed, it took longer than anticipated because of weather, and they broke my luggage.

Horrifying! And I am almost 2 million miles with United. Late by 3 1/2 hours. Worst: after two hours on the plane waiting, they decided that one of the tires had been damaged and then decided to change it. Another hour and a half to change the tire!!!!! NO EXCUSE FOR THIS. The crew didn't even offer a glass of water until we had been on the plane for FIVE hours. This is the worst airline in the world. I'm simply stuck because they fly on the only routes I need.

Gate got changed about 4 times. Very confusing and very crowded. If you don’t have wifi to help get updates, you can be in deep trouble.

Attendants zipped through cabin so fast hardly anyone got the water they told us we could have in the short flight. Nothing else was offered.

Sucks ! All three flights I was on this trip were delayed.

The flight attendants were unhelpful. It was a packed flight, and usually a flight attendant would help find a spot in the bin for your carry on or shift things around. Neither made any effort to do so. Also, I had to then check my bag. I was told it would be on the carousel in YYZ, but it came up on the jetway. So lucky I saw others standing around for their bags. I would have walked straight past this and on to the carousel. They could have at least told me that they had given me wrong information. Very unsatisfactory.

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

Information on your arrival and departure airports

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.