SEA - WAS

C$ 179 Find Cheap Flights from Seattle to Washington, D.C.

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 12/1. 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.

 
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$ 297
Overall average: C$ 560
United Airlines
Fri 16/1Mon 19/1
SEA - IAD • Direct
Cheapest one-way flights
C$ 179
Typical prices: C$ 293-C$ 631
Delta
Mon 12/1
SEA - DCA • 1 stop
Our travellers' advice
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
Alaska's 20-minute baggage guarantee offers rewards.
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$ 300 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Top routes
SEA-DCA
Cheapest • 45% average savings
SEA-DCA
Most popular
Insights
Insights
Insights
Insights
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
August
Cheapest • 13% 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-WAS)

 
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$ 297United Airlines
Wed, 7 Jan - Thu, 8 Jan
Alaska Airlines Logo
7:15 a.m. - 9:00 p.m.
SEA
-
DCA
10h 45m1 stop
Alaska Airlines Logo
6:56 p.m. - 9:18 a.m.
DCA
-
SEA
17h 22m1 stop
C$ 300Alaska 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$ 300United Airlines
Sat, 17 Jan - Tue, 20 Jan
Delta Logo
6:05 a.m. - 6:56 p.m.
SEA
-
IAD
9h 51m1 stop
Delta Logo
2:15 p.m. - 8:46 p.m.
IAD
-
SEA
9h 31m1 stop
C$ 302Delta
Thu, 8 Jan - Sun, 11 Jan
Southwest Logo
6:45 a.m. - 6:20 p.m.
SEA
-
DCA
8h 35m1 stop
Southwest Logo
6:00 a.m. - 10:50 a.m.
DCA
-
SEA
7h 50m1 stop
C$ 302Southwest
Fri, 9 Jan - Sat, 17 Jan
Delta Logo
6:05 a.m. - 5:04 p.m.
SEA
-
DCA
7h 59m1 stop
Delta Logo
4:00 p.m. - 10:50 p.m.
DCA
-
SEA
9h 50m1 stop
C$ 304Delta
Fri, 9 Jan - Sat, 17 Jan
Delta Logo
1:30 p.m. - 11:06 p.m.
SEA
-
IAD
6h 36m1 stop
Delta Logo
5:27 p.m. - 9:49 p.m.
IAD
-
SEA
7h 22m1 stop
C$ 304Delta
Sun, 1 Feb - Tue, 10 Feb
United Airlines Logo
7:00 a.m. - 5:35 p.m.
SEA
-
IAD
7h 35m1 stop
United Airlines Logo
5:55 p.m. - 8:57 p.m.
IAD
-
SEA
6h 02mdirect
C$ 314United Airlines
Sat, 31 Jan - Tue, 3 Feb
Alaska Airlines Logo
8:00 a.m. - 4:09 p.m.
SEA
-
DCA
5h 09mdirect
Alaska Airlines Logo
5:09 p.m. - 10:33 p.m.
DCA
-
SEA
8h 24m1 stop
C$ 315Alaska 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
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 Seattle to Washington, D.C. flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest return flight from Seattle to Washington, D.C. costs C$ 325 on the route between Seattle (SEA) and Washington, D.C. Reagan-National Airport (DCA). Over the past month, this route was, on average, 45% cheaper than other Seattle-Washington, D.C. routes. It is also the most popular route.

What’s the cheapest day of the week to fly from Seattle to Washington, D.C.?

The average price of all round-trip flights from Seattle to Washington, D.C. clicked on KAYAK for each day over the last 12 months.

When flying from Seattle to Washington, D.C., you should consider leaving on a Thursday and avoid Sundays if you are looking for the best rates. For your return to Seattle, you’ll find the best rates on Thursdays and the most expensive ones on Saturdays.

What is the cheapest month to fly from Seattle to Washington, D.C.?

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., 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. is August, where tickets cost C$ 478 (return) on average. On the other hand, the most expensive months are January and December, where the average cost of round-trip tickets is C$ 719 and C$ 629 respectively.

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

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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at C$ 242 on average.

How far in advance should I book a flight from Seattle to Washington, D.C.?

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., 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., 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
Alaska Airlines

Alaska's 20-minute baggage guarantee offers a discount or 2,500 miles if delayed.


Enjoy free wine tastings in Washington with your boarding pass and Mileage Plan membership.

United Airlines

Opt for Economy Plus for 15 cm more legroom than standard economy seats.


Purchase Priority Boarding to ensure overhead bin space, placing you in Zone 2.

Airports
SEA

Use the SEA Spot Saver for expedited security screening without a paid program. Book online or via the flySEA app.

IAD

The Silver Line Metro connects IAD to downtown D.C. in about 50 minutes, offering a convenient and cost-effective option.

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

Good to know

Low seasonJanuary
Cheapest flightC$ 179
Best time to beat the crowds but there is an average 30% increase in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Seattle to Reagan Washington National 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 flights from Seattle to Washington, D.C.

  • What is the cheapest flight from Seattle to Washington, D.C.?

    In the last 3 days, the lowest price for a flight from Seattle to Washington, D.C. was C$ 179 for a one-way ticket and C$ 297 for a round-trip.

  • Which airports will I be using when flying from Seattle to Washington, D.C.?

    On your way to Washington, D.C., you’ll fly out from Seattle/Tacoma Intl. You’ll be landing in one of Washington, D.C.’s 2 airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl.

  • Which airlines offer Wi-Fi service onboard planes from Seattle to Washington, D.C.?

    Alaska Airlines, Hawaiian Airlines, and Delta offer inflight Wi-Fi service on the Seattle to Washington, D.C. flight route.

  • Which aircraft models fly most regularly from Seattle to Washington, D.C.?

    The Boeing 737-800 Passenger/BBJ2 (winglets) is the aircraft model that flies most regularly on the Seattle to Washington, D.C. flight route.

  • Which airline alliances offer flights from Seattle to Washington, D.C.?

    oneworld is the only airline alliance operating flights between Seattle and Washington, D.C..

  • On which days can I fly direct from Seattle to Washington, D.C.?

    There are direct flights from Seattle to Washington, D.C. on a daily basis.

  • Which is the best airline for flights from Seattle to Washington, D.C., Delta or Frontier?

    The two airlines most popular with KAYAK users for flights from Seattle to Washington, D.C. are Delta and Frontier. With an average price for the route of C$ 313 and an overall rating of 7.9, Delta is the most popular choice. Frontier is also a great choice for the route, with an average price of C$ 372 and an overall rating of 5.8.

  • How does KAYAK find such low prices on flights from Seattle to Washington, D.C.?

    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, D.C..

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to Washington, D.C.?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Washington, D.C. from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to Washington, D.C.?

    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, D.C. 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, D.C.?

    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, D.C. 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, D.C.?

 
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..
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Washington, D.C., which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Washington, D.C.

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. 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.
7.9
DeltaOverall score based on 8006 reviews
8.5Crew
7.9Entertainment
8.1Boarding
7.9Comfort
7.3Food
Airline reviews

Original flight was cancelled and when i was rebooked by the airline, they couldn't seat me in the same type of seat as I had originally booked (went from window/aisle to middle/middle and one was a bulkhead seat, and other wasn't in the same class)

6.0 GoodJeff, Dec 2025
JFK - MIA
Read more Delta reviews

Original flight was cancelled and when i was rebooked by the airline, they couldn't seat me in the same type of seat as I had originally booked (went from window/aisle to middle/middle and one was a bulkhead seat, and other wasn't in the same class)

Lady Pilot was perfect in every way wheels up to wheels down communication, professionalism, excellent on time departure and on time arrival, excellent communication! Fantastic job with Superb attitude!!

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

I fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Good seats in Main cabin, excellent service and excellent landing

My flight was cancelled with no explanation after I had already cleared security. I was given 4 options to rebook, only one being non-stop like I had paid for. I grabbed it. It was 4 plus hours later and then took off even later. Biggest complaint is that I booked early and had an aisle seat. They gave me a "window" seat in front of the exit row, so the seat did not decline. I weigh all of 103 #s and it was tight for me! For what I paid, I feel I was kind of ripped off. I think they should have given me the empty comfort seat for the inconvenience. There was no apology nor any explanation as to why the flight was cancelled. My guess is it benefitted Delta in some way.

Very smooth, on-time, and pleasantly uneventful flight. The team at the gate and on board were professional and genuinely courteous. The pilot kept us well updated throughout, and both takeoff and landing were steady and enjoyable without any drama. Just a good, solid flight. Thank you! 💗

Staff was exceptional! Everyone was kind, professional and friendly making the trip very pleasant. Thank you!

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

Not clean and was told I would get a great seat and it was not great at all

Flight got delayed for 5 hours no good explanation was offered ;(

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

Better than expected. Staff were friendly and nice on both flights.

There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

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

Information on your arrival and departure airports