SEA - IAD

C$ 178 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 24/1. 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

Save 23% 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.

Everything you should know

Cheapest round-trip
C$ 298
Typical prices: C$ 396-C$ 920
United Airlines
Fri 16/1Mon 19/1
SEA - IAD • Direct
Cheapest one-way flights
C$ 178
Typical prices: C$ 225-C$ 491
American Airlines
Sat 24/1
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
Delta
Cheapest • from C$ 302 (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 55% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 19% 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.

Fri, 16 Jan - Mon, 19 Jan
United Airlines Logo
8:10 a.m. - 4:16 p.m.
SEA
-
IAD
5h 06mdirect
United Airlines Logo
5:55 p.m. - 8:57 p.m.
IAD
-
SEA
6h 02mdirect
C$ 298United Airlines
Thu, 1 Jan - Tue, 6 Jan
United Airlines Logo
11:15 p.m. - 7:11 a.m.
SEA
-
IAD
4h 56mdirect
United Airlines Logo
5:55 p.m. - 8:57 p.m.
IAD
-
SEA
6h 02mdirect
C$ 301United Airlines
Thu, 22 Jan - Sun, 25 Jan
Delta Logo
11:10 p.m. - 11:52 a.m.
SEA
-
IAD
9h 42m1 stop
Delta Logo
3:42 p.m. - 11:15 p.m.
IAD
-
SEA
10h 33m1 stop
C$ 302Delta
Fri, 16 Jan - Mon, 19 Jan
United Airlines Logo
8:10 a.m. - 4:16 p.m.
SEA
-
IAD
5h 06mdirect
United Airlines Logo
5:17 p.m. - 10:43 p.m.
IAD
-
SEA
8h 26m1 stop
C$ 309United Airlines
Fri, 16 Jan - Sat, 17 Jan
United Airlines Logo
7:30 p.m. - 7:35 a.m.
SEA
-
IAD
9h 05m1 stop
United Airlines Logo
5:55 p.m. - 8:57 p.m.
IAD
-
SEA
6h 02mdirect
C$ 314United Airlines
Thu, 15 Jan - Sun, 18 Jan
United Airlines Logo
7:00 a.m. - 5:35 p.m.
SEA
-
IAD
7h 35m1 stop
United Airlines Logo
5:17 p.m. - 10:43 p.m.
IAD
-
SEA
8h 26m1 stop
C$ 321United Airlines
Thu, 12 Feb - Sun, 15 Feb
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
Tue, 10 Feb - Thu, 26 Feb
Alaska Airlines Logo
8:30 a.m. - 4:26 p.m.
SEA
-
IAD
4h 56mdirect
Alaska Airlines Logo
7:05 a.m. - 10:05 a.m.
IAD
-
SEA
6h 00mdirect
C$ 328Alaska Airlines
Sun, 15 Feb - Thu, 19 Feb
Delta Logo
3:20 p.m. - 11:10 p.m.
SEA
-
IAD
4h 50mdirect
Delta Logo
7:30 a.m. - 10:29 a.m.
IAD
-
SEA
5h 59mdirect
C$ 330Delta
Thu, 8 Jan - Thu, 15 Jan
United Airlines Logo
8:10 a.m. - 4:16 p.m.
SEA
-
IAD
5h 06mdirect
United Airlines Logo
5:55 p.m. - 8:57 p.m.
IAD
-
SEA
6h 02mdirect
C$ 335United 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.

How much is a round-trip flight from Seattle to Washington, D.C. Dulles Intl Airport?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Seattle to Washington, D.C. Dulles Intl Airport departing in January.

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 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 October, where tickets cost C$ 448 (return) on average. On the other hand, the most expensive months are November and December, where the average cost of round-trip tickets is C$ 663 and C$ 662 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 26 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.
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.

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.

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

Good to know

Low seasonJanuary
Cheapest flightC$ 178
Most popular time to fly and prices are also 11% 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$ 178 for a one-way ticket and C$ 298 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, Hawaiian Airlines, Delta, JetBlue, American Airlines, Lufthansa, and United Airlines.

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

    The Boeing 737-800 Passenger/BBJ2 (winglets) 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 is the only airline alliance operating flights between Seattle and Washington Dulles Airport.

  • 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$ 390 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$ 362 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.

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 11432 reviews
8.5Crew
8.1Boarding
7.8Comfort
7.1Food
7.0Entertainment
Airline reviews

I wasn’t assigned a seat until last minute even though I checked in 24 hours before the flight and was told I might not be able to get on the flight! The leg room and seat room in the flight was abysmal. The service both at boarding and on the flight was very mediocre and not particularly friendly.

4.0 OkayAnonymous, Dec 2025
SEA - EWR
Read more Alaska Airlines reviews

I wasn’t assigned a seat until last minute even though I checked in 24 hours before the flight and was told I might not be able to get on the flight! The leg room and seat room in the flight was abysmal. The service both at boarding and on the flight was very mediocre and not particularly friendly.

Late boarding, older plane. Great flight, no issues. Very cold inside the plane.

The plane was old so the seats were very worn out. The seats were hard, uncomfortable, and caused me actual pain. The lights were too bright. The flight itself was fine.

1. Denial of Basic Needs (SEA): Upon arrival in Seattle, the wheelchair attendant refused my urgent request to use the restroom, insisting on scanning documents first. She eventually took me to a restroom but then abandoned me and my autistic son at an unstaffed, deserted gate for over four hours. When I called the accommodation line for help, I was told to "get someone's attention," which was impossible. My son, traumatized by the prospect of me yelling for help, was forced to wander the terminal to find assistance. 2. Revocation of Accommodations & Threats: At the gate, an agent stated I had no accommodations on file, despite my previous leg having them. When I showed the app (where my bulkhead seat was erased and replaced with Row 14), he denied the evidence. When I attempted to advocate for my immobilized leg, he threatened to "yank me from the flight" if I said one more word. He coerced me into agreeing that I was "asking for accommodations for the first time" before he would allow assistance, effectively forcing me to falsify the situation under duress. I complied only out of fear of being stranded in a strange city. 3. On-Board Negligence and Injury: Because my bulkhead seat was revoked, I was forced into Row 14. With my leg immobilized and unable to bend, it extended into the aisle. During boarding and the flight: 16 different passengers tripped over my injured leg. 6 rolled luggage bags were pulled over my injured leg. The Flight Attendant (FA) was one of the people who tripped and drove luggage over me. I reported the issue to the FA after 10 trips and 3 luggage impacts. He ignored me. He only addressed me later to ask me to move my immobilized leg for beverage service. I informed him again: "16 people have tripped, 6 luggage runovers, I cannot bend it." He provided no medical aid and no incident report. 4. Resolution and Trauma: Eventually, a different employee noticed my distress and my original paper boarding pass showing the correct bulkhead assignment. He asked me to move up. I broke down in tears, terrified that moving would cause the gate agent to remove me from the plane as threatened. We were eventually moved to the bulkhead, but the damage was done. My autistic son was traumatized by watching his mother be trampled and threatened. 5. Post-Flight: I called to report these injuries, but was disconnected after a 45-minute hold. I require a formal record of this injury and these violations.

Larger seats with a bit more room would be good! Thanks for all your hard work. I think we are all feeling a bit down these days economically and your positive attitudes, both from SJC to Seattle and from Seattle to Bozeman makes more of a difference than you can see! Thank you and Merry Christmas! I hope all your financial needs are met and that very good things come your way.

We flew economy, it was what I expected. The seats are too upright for me

I purchased a 1st class ticket and unfortunately the main flight attendant was not the best and seemed more interested in her phone than the passengers at times. Then the plane didn’t get restocked and the only snacks for this flight were pretzels. However I would like to say that the rest of the flight crew and ground crew at the airport we’re great, especially the people that wheeled me around the airport some and then the one getting me to the plane and the automated wheelchair that wheeled me through the airport.

Typical domestic flight. No entertainment. You have to use your own devices and provided entertainment didn’t work. Pretzels and water of flight over 4 hours is unacceptable. Meals should be provided on long flights. But it’s about the money and not customer service. You should just issue the bag of pretzels at the gate and water bottle in seat and just do away with flight attendants because they do nothing on domestic flights

Very good. Easy check in, attentive flight attendant, and on time departure/landing.

Again Alaskan and Hawaiian need to consolidate check-in, allow seat reservations on both flights. I wound up in last row because I couldn’t reserve better seat.

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.

The flight was CANCELED!!! Can’t get much more “poor” than that. I had to switch to American Airlines, add another layover and got home in Honolulu 4 hours later than I was supposed to be home. One bright spot was Josh with Alaska Airlines at SFO. He got me on a United Flight that got me home a few hours before I would have. Without him I would have gotten home almost 7 hours after my originally scheduled flight.

Canceled my flight within 24 hours, causing me arriving home midnight. Will never book Hawaiian airlines anymore

I like Hawaiian, it was great that they had good internet connection across the Pacific Ocean, thanks to Star Link satellites. The seating was comfortable, ( I was in economy ). Maybe I missed it, but I only got offered a beverage once. It was a nonstop flight KOA to SMF. I would take it again next time I go that way.

I always love flying Hawaii and I have nothing to add

Previously flown Hawaiian Airlines on similar routes, I found Alaska Airlines to be noticeably more comfortable. The seats on Alaska Airlines provided better support and cushioning, which made a significant difference on the long flight to the islands. When you’re spending 5-6 hours in the air, seat comfort really matters, and Alaska Airlines delivered where it counts. After comparing both carriers, I’ve decided to book with Alaska Airlines for all my future Hawaii trips. The superior seat comfort alone makes it worth choosing Alaska over Hawaiian Airlines. If you’re planning a trip to Hawaii and prioritizing comfort, I’d recommend giving Alaska Airlines a try. You won’t be disappointed. Highly recommended for Hawaii travel!

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

Information on your arrival and departure airports