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Cheap flights from Seattle to Washington, D.C. from $141

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Washington, D.C. departing on 12/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Cheap round-trip flights

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Delta Logo
3:47 pm - 9:49 amSEA-IAD
15h 02m1 stop
Delta Logo
7:00 am - 10:04 amIAD-SEA
6h 04mnonstop
$252Delta
Find Deal
Wed, Dec 24 - Mon, Jan 5
United Airlines Logo
8:00 am - 4:07 pmSEA-IAD
5h 07mnonstop
United Airlines Logo
5:55 pm - 8:54 pmIAD-SEA
5h 59mnonstop
$253United Airlines
Find Deal
Wed, Nov 19 - Sun, Nov 23
Hawaiian Airlines Logo
8:40 am - 4:36 pmSEA-IAD
4h 56mnonstop
Hawaiian Airlines Logo
7:34 am - 10:35 amIAD-SEA
6h 01mnonstop
$254Hawaiian Airlines
Find Deal
Sat, Dec 6 - Sat, Dec 13
Hawaiian Airlines Logo
10:11 pm - 6:06 amSEA-IAD
4h 55mnonstop
Hawaiian Airlines Logo
7:34 am - 10:35 amIAD-SEA
6h 01mnonstop
$256Hawaiian Airlines
Find Deal
Sun, Dec 7 - Sun, Dec 14
Delta Logo
4:59 pm - 12:54 amSEA-IAD
4h 55mnonstop
Delta Logo
7:15 am - 10:19 amIAD-SEA
6h 04mnonstop
$257Delta
Find Deal
Thu, Nov 13 - Wed, Nov 19
United Airlines Logo
8:00 am - 4:07 pmSEA-IAD
5h 07mnonstop
United Airlines Logo
8:35 am - 3:29 pmIAD-SEA
9h 54m1 stop
$267United Airlines
Find Deal
Fri, Nov 28 - Sat, Dec 6
American Airlines Logo
12:41 am - 10:59 pmSEA-IAD
19h 18m1 stop
American Airlines Logo
6:25 am - 12:47 pmIAD-SEA
9h 22m1 stop
$271American Airlines
Find Deal
Tue, Dec 2 - Sat, Dec 6
American Airlines Logo
12:31 am - 4:18 pmSEA-IAD
12h 47m1 stop
American Airlines Logo
2:16 pm - 8:37 pmIAD-SEA
9h 21m1 stop
$272American Airlines
Find Deal
Fri, Dec 5 - Wed, Dec 10
Alaska Airlines Logo
10:14 pm - 6:13 amSEA-IAD
4h 59mnonstop
Alaska Airlines Logo
6:04 pm - 9:08 pmIAD-SEA
6h 04mnonstop
$273Alaska Airlines
Find Deal
Mon, Dec 22 - Sat, Jan 17
Alaska Airlines Logo
8:40 am - 4:36 pmSEA-IAD
4h 56mnonstop
Alaska Airlines Logo
7:34 am - 10:35 amIAD-SEA
6h 01mnonstop
$293Alaska Airlines
Find Deal
Tue, Dec 2 - Sat, Dec 6

Southwest flights from Seattle to Washington, D.C. Dulles Intl Airport

Our best Southwest deals on Seattle to Washington, D.C. Dulles Intl Airport flight tickets
Southwest
Jan 13
SEA8:45 amSeattle/Tacoma Intl
10h 10m
2 stops
IAD9:55 pmWashington, D.C. Dulles Intl
Jan 16
IAD5:40 pmWashington, D.C. Dulles Intl
8h 10m
1 stop
SEA10:50 pmSeattle/Tacoma Intl
$263
Find similar
Southwest
Jan 23
SEA5:15 amSeattle/Tacoma Intl
8h 35m
1 stop
IAD4:50 pmWashington, D.C. Dulles Intl
Jan 25
IAD5:30 amWashington, D.C. Dulles Intl
16h 00m
2 stops
SEA6:30 pmSeattle/Tacoma Intl
$265
Find similar
Southwest
Dec 11
SEA5:40 amSeattle/Tacoma Intl
13h 20m
1 stop
IAD10:00 pmWashington, D.C. Dulles Intl
Dec 18
IAD1:50 pmWashington, D.C. Dulles Intl
13h 45m
1 stop
SEA12:35 amSeattle/Tacoma Intl
$292
Find similar

American Airlines flights from Seattle to Washington, D.C. Dulles Intl Airport

Our best American Airlines deals on Seattle to Washington, D.C. Dulles Intl Airport flight tickets
American Airlines
Dec 2
SEA12:41 amSeattle/Tacoma Intl
19h 18m
1 stop
IAD10:59 pmWashington, D.C. Dulles Intl
Dec 6
IAD6:25 amWashington, D.C. Dulles Intl
9h 22m
1 stop
SEA12:47 pmSeattle/Tacoma Intl
$271
Find similar
American Airlines
Dec 5
SEA12:31 amSeattle/Tacoma Intl
12h 47m
1 stop
IAD4:18 pmWashington, D.C. Dulles Intl
Dec 10
IAD2:16 pmWashington, D.C. Dulles Intl
9h 21m
1 stop
SEA8:37 pmSeattle/Tacoma Intl
$272
Find similar
American Airlines
Dec 11
SEA12:31 amSeattle/Tacoma Intl
19h 28m
1 stop
IAD10:59 pmWashington, D.C. Dulles Intl
Dec 16
IAD6:00 amWashington, D.C. Dulles Intl
10h 06m
1 stop
SEA1:06 pmSeattle/Tacoma Intl
$274
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to Washington, D.C. Dulles Intl Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated October 23, 2025.
Use the filters below to find and compare flights from Seattle to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 12/24

3:47 pm-9:49 am

1 stop15h 02m

Washington, D.C. Dulles Intl

Mon 1/5

7:00 am-10:04 am

Nonstop6h 04m

$252

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 11/19

8:00 am-4:07 pm

Nonstop5h 07m

Washington, D.C. Dulles Intl

Sun 11/23

5:55 pm-8:54 pm

Nonstop5h 59m

$253

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 12/6

8:40 am-4:36 pm

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sat 12/13

7:34 am-10:35 am

Nonstop6h 01m

$254

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 12/7

10:11 pm-6:06 am

Nonstop4h 55m

Washington, D.C. Dulles Intl

Sun 12/14

7:34 am-10:35 am

Nonstop6h 01m

$256

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 11/13

4:59 pm-12:54 am

Nonstop4h 55m

Washington, D.C. Dulles Intl

Wed 11/19

7:15 am-10:19 am

Nonstop6h 04m

$257

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 11/28

8:00 am-4:07 pm

Nonstop5h 07m

Washington, D.C. Dulles Intl

Sat 12/6

8:35 am-3:29 pm

1 stop9h 54m

$267

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 12/2

12:41 am-10:59 pm

1 stop19h 18m

Washington, D.C. Dulles Intl

Sat 12/6

6:25 am-12:47 pm

1 stop9h 22m

$271

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 12/5

12:31 am-4:18 pm

1 stop12h 47m

Washington, D.C. Dulles Intl

Wed 12/10

2:16 pm-8:37 pm

1 stop9h 21m

$272

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 12/22

10:14 pm-6:13 am

Nonstop4h 59m

Washington, D.C. Dulles Intl

Sat 1/17

6:04 pm-9:08 pm

Nonstop6h 04m

$273

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 12/2

8:40 am-4:36 pm

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sat 12/6

7:34 am-10:35 am

Nonstop6h 01m

$293

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Washington, D.C. from

How to get the cheapest flight ticket from Seattle to Washington, D.C. Dulles Intl Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Washington, D.C. Dulles Intl Airport?

In general, February is the cheapest month to fly from Seattle to Washington, D.C. Dulles Intl Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $344. If you aren’t able to travel to Washington, D.C. Dulles Intl Airport during the month of February, then flying in October is also cheap. Prices for this month can be found on momondo for an average of $352.

What is the cheapest day to depart on your flight to Washington, D.C. Dulles Intl Airport?

Our data shows that Wednesday is the least expensive day to fly to Washington, D.C. Dulles Intl Airport. Tickets to fly out on this day can be as low as $442. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Washington, D.C. Dulles Intl Airport for around $623.

What is the cheapest time of day to depart on your flight to Washington, D.C. Dulles Intl Airport?

Flying to Washington, D.C. Dulles Intl Airport from Seattle in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $361 when looking at flights departing in the afternoon. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $538 on average. Flights to Washington, D.C. Dulles Intl Airport from Seattle in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

What is the cheapest Seattle/Tacoma Intl to Washington, D.C. Dulles Intl flight route?

Fly from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl for the best Seattle/Tacoma Intl - Washington, D.C. Dulles Intl flight prices

How far in advance should I book a flight to Washington, D.C. Dulles Intl Airport?

You are more likely to see cheaper flights to Washington, D.C. Dulles Intl Airport from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. Dulles Intl Airport for around $404 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. Dulles Intl Airport from Seattle for as low as $324 on momondo.

What cabin class options are available on Seattle/Tacoma Intl to Washington, D.C. Dulles Intl flights?

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Washington, D.C. Dulles Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Seattle to Washington, D.C. Dulles Intl Airport flights?

No. A direct flight is the cheapest option for a flight between Seattle to Washington, D.C. Dulles Intl Airport.

How have Seattle to Washington, D.C. Dulles Intl Airport flight prices changed over time?

As of October 2025, prices for Seattle to Washington, D.C. Dulles Intl Airport flights are approximately 6% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to Washington, D.C. Dulles Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to Washington, D.C. Dulles Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to Washington, D.C. Dulles Intl Airport (SEA to IAD) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Washington, D.C. Dulles Intl Airport

Best Price Found

$188

Fastest flight time

4h 52m

Direct flights

Every day
The best one-way flight to Washington, D.C. Dulles Intl Airport from Seattle in the past 72 hours is $188. The best round-trip flight deal from Seattle to Washington, D.C. Dulles Intl Airport found on momondo in the last 72 hours is $308.
The fastest flight from Seattle to Washington, D.C. Dulles Intl Airport takes 4h 52m
Direct flights go from Seattle to Washington, D.C. Dulles Intl Airport every day.
Search flight deals

  • How far is Seattle/Tacoma Intl to Washington, D.C. Dulles Intl by plane?

    There are 2299.7 mi between Seattle/Tacoma Intl and Washington, D.C. Dulles Intl. A reasonable flight in good conditions will take 4h 54m.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Seattle/Tacoma Intl Airport to Washington, D.C. Dulles Intl Airport.

  • What documentation or ID do you need to fly to Washington, D.C. Dulles Intl Airport?

    The travel and health documents required for your trip to Washington, D.C. Dulles Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Washington, D.C. Dulles Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Seattle to Washington, D.C. Dulles Intl Airport?

  • What is the most popular airline from Seattle to Washington, D.C. Dulles Intl Airport?

Best airlines flying from Seattle to Washington, D.C. Dulles Intl Airport

Compare and see reviews for airlines that fly from Seattle to Washington, D.C. Dulles Intl Airport with momondo
Airline
Rating
Free Cancellation
Price
Hawaiian AirlinesPriceFrom $143Free CancellationRating
7.8
2,789 reviews
Search Hawaiian Airlines flights
FrontierPriceFrom $188Free CancellationRating
5.8
3,128 reviews
Search Frontier flights
DeltaPriceFrom $188Free CancellationRating
7.9
7,982 reviews
Search Delta flights
American AirlinesPriceFrom $256Free CancellationRating
7.2
11,033 reviews
Search American Airlines flights
United AirlinesPriceFrom $260Free CancellationRating
7.4
8,995 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $277Free CancellationRating
8.0
11,161 reviews
Search Alaska Airlines flights

  • Alaska Airlines Flights From Seattle to Washington, D.C. Dulles Intl Airport

    Across 4 Alaska Airlines flights from Seattle to Washington, D.C. Dulles Intl Airport this week, the average price was $423, with the best Alaska Airlines deals starting from $277 round-trip. 11,161 users have rated Alaska Airlines on momondo, with an average score of 8.0/10.

  • Delta Flights From Seattle to Washington, D.C. Dulles Intl Airport

    Delta is also a popular choice for this route. Delta flight deals for Seattle to Washington, D.C. Dulles Intl Airport start from as low as $188 round-trip, depending on your selected dates, with average Delta deals seen on momondo around $381. Delta operates 7 flights to Washington, D.C. Dulles Intl Airport from Seattle in an average week. Users have rated it 7.9/10 across 7,982 reviews.

Traveling to a place near Washington, D.C.?

Book flights to Washington, D.C. if you plan to visit one of these locations
Alexandria
National Harbor
Gettysburg
Arlington
Winchester
Woodbridge
Waldorf
Tysons
Laurel
Colonial Beach
Silver Spring
Fredericksburg
Harpers Ferry
Towson
Rockville
Manassas
Reston
Fairfax
Gaithersburg
Sterling

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Washington, D.C.?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Washington, D.C.. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Seattle to Washington, D.C. with flexible booking policies on momondo?

Yes. All flights to Washington, D.C. from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Seattle to Washington, D.C.?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to Washington, D.C..

I’m not ready to book a flight from Seattle to Washington, D.C. right now. Can momondo alert me if prices change?

If you are not ready to book a flight from Seattle to Washington, D.C. now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Washington, D.C. and let you know when they change.

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