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Cheap flights from Seattle to Washington, D.C. from $117

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 10/16. 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

Frontier Logo
12:05 pm - 9:17 amSEA-IAD
18h 12m2 stops
Frontier Logo
1:55 pm - 12:30 amIAD-SEA
13h 35m2 stops
$236Frontier
Find Deal
Thu, Sep 11 - Mon, Sep 15
Frontier Logo
9:22 pm - 4:34 pmSEA-IAD
16h 12m2 stops
Frontier Logo
10:29 pm - 12:13 pmIAD-SEA
16h 44m2 stops
$246Frontier
Find Deal
Thu, Oct 30 - Sun, Nov 2
Hawaiian Airlines Logo
8:44 am - 4:40 pmSEA-IAD
4h 56mnonstop
Hawaiian Airlines Logo
7:43 am - 10:35 amIAD-SEA
5h 52mnonstop
$263Hawaiian Airlines
Find Deal
Wed, Nov 5 - Sun, Nov 9
Alaska Airlines Logo
4:20 pm - 12:23 amSEA-IAD
5h 03mnonstop
Alaska Airlines Logo
7:00 am - 9:40 amIAD-SEA
5h 40mnonstop
$265Alaska Airlines
Find Deal
Thu, Sep 25 - Wed, Oct 1
Hawaiian Airlines Logo
11:30 pm - 7:33 amSEA-IAD
5h 03mnonstop
Hawaiian Airlines Logo
6:25 am - 9:08 amIAD-SEA
5h 43mnonstop
$273Hawaiian Airlines
Find Deal
Wed, Oct 1 - Wed, Oct 8
United Airlines Logo
11:40 pm - 11:55 amSEA-IAD
9h 15m1 stop
United Airlines Logo
1:05 pm - 3:52 pmIAD-SEA
5h 47mnonstop
$282United Airlines
Find Deal
Fri, Oct 24 - Sat, Oct 25
United Airlines Logo
1:05 pm - 12:45 amSEA-IAD
8h 40m1 stop
United Airlines Logo
5:55 pm - 8:42 pmIAD-SEA
5h 47mnonstop
$287United Airlines
Find Deal
Fri, Sep 12 - Sun, Sep 21
Alaska Airlines Logo
7:59 pm - 4:52 pmSEA-IAD
17h 53m1 stop
Alaska Airlines Logo
5:52 pm - 10:20 amIAD-SEA
19h 28m1 stop
$296Alaska Airlines
Find Deal
Tue, Sep 16 - Tue, Sep 23
Delta Logo
9:55 pm - 6:01 amSEA-IAD
5h 06mnonstop
Delta Logo
7:35 am - 10:28 amIAD-SEA
5h 53mnonstop
$317Delta
Find Deal
Sun, Sep 21 - Fri, Oct 24
Delta Logo
9:55 pm - 5:55 amSEA-IAD
5h 00mnonstop
Delta Logo
8:17 pm - 10:15 amIAD-SEA
16h 58m1 stop
$326Delta
Find Deal
Mon, Sep 8 - Tue, Sep 16

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

Our best Frontier deals on Seattle to Washington, D.C. Dulles Intl Airport flight tickets
Frontier
Sep 11
SEA12:05 pmSeattle/Tacoma Intl
18h 12m
2 stops
IAD9:17 amWashington, D.C. Dulles Intl
Sep 15
IAD1:55 pmWashington, D.C. Dulles Intl
13h 35m
2 stops
SEA12:30 amSeattle/Tacoma Intl
$236
Find similar
Frontier
Oct 30
SEA9:22 pmSeattle/Tacoma Intl
16h 12m
2 stops
IAD4:34 pmWashington, D.C. Dulles Intl
Nov 2
IAD10:29 pmWashington, D.C. Dulles Intl
16h 44m
2 stops
SEA12:13 pmSeattle/Tacoma Intl
$246
Find similar
Frontier
Oct 1
SEA7:00 amSeattle/Tacoma Intl
23h 17m
2 stops
IAD9:17 amWashington, D.C. Dulles Intl
Oct 2
IAD1:55 pmWashington, D.C. Dulles Intl
13h 35m
2 stops
SEA12:30 amSeattle/Tacoma Intl
$248
Find similar

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

Our best Hawaiian Airlines deals on Seattle to Washington, D.C. Dulles Intl Airport flight tickets
Hawaiian Airlines
Nov 5
SEA8:44 amSeattle/Tacoma Intl
4h 56m
IAD4:40 pmWashington, D.C. Dulles Intl
Nov 9
IAD7:43 amWashington, D.C. Dulles Intl
5h 52m
SEA10:35 amSeattle/Tacoma Intl
$263
Find similar
Hawaiian Airlines
Oct 1
SEA11:30 pmSeattle/Tacoma Intl
5h 03m
IAD7:33 amWashington, D.C. Dulles Intl
Oct 8
IAD6:25 amWashington, D.C. Dulles Intl
5h 43m
SEA9:08 amSeattle/Tacoma Intl
$273
Find similar
Hawaiian Airlines
Sep 22
SEA4:20 pmSeattle/Tacoma Intl
5h 03m
IAD12:23 amWashington, D.C. Dulles Intl
Sep 30
IAD6:09 pmWashington, D.C. Dulles Intl
5h 47m
SEA8:56 pmSeattle/Tacoma Intl
$276
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 August 18, 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

Thu 9/11

12:05 pm-9:17 am

2 stops18h 12m

Washington, D.C. Dulles Intl

Mon 9/15

1:55 pm-12:30 am

2 stops13h 35m

$236

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 10/30

9:22 pm-4:34 pm

2 stops16h 12m

Washington, D.C. Dulles Intl

Sun 11/2

10:29 pm-12:13 pm

2 stops16h 44m

$246

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 11/5

8:44 am-4:40 pm

Nonstop4h 56m

Washington, D.C. Dulles Intl

Sun 11/9

7:43 am-10:35 am

Nonstop5h 52m

$263

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 9/25

4:20 pm-12:23 am

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 10/1

7:00 am-9:40 am

Nonstop5h 40m

$265

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 10/1

11:30 pm-7:33 am

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 10/8

6:25 am-9:08 am

Nonstop5h 43m

$273

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 10/24

11:40 pm-11:55 am

1 stop9h 15m

Washington, D.C. Dulles Intl

Sat 10/25

1:05 pm-3:52 pm

Nonstop5h 47m

$282

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 9/12

1:05 pm-12:45 am

1 stop8h 40m

Washington, D.C. Dulles Intl

Sun 9/21

5:55 pm-8:42 pm

Nonstop5h 47m

$287

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 9/16

7:59 pm-4:52 pm

1 stop17h 53m

Washington, D.C. Dulles Intl

Tue 9/23

5:52 pm-10:20 am

1 stop19h 28m

$296

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sun 9/21

9:55 pm-6:01 am

Nonstop5h 06m

Washington, D.C. Dulles Intl

Fri 10/24

7:35 am-10:28 am

Nonstop5h 53m

$317

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Mon 9/8

9:55 pm-5:55 am

Nonstop5h 00m

Washington, D.C. Dulles Intl

Tue 9/16

8:17 pm-10:15 am

1 stop16h 58m

$326

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, October 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 $343. If you aren’t able to travel to Washington, D.C. Dulles Intl Airport during the month of October, then flying in February is also cheap. Prices for this month can be found on momondo for an average of $344.

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

Our data shows that Thursday 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 $441. 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 $572.

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 $362 when looking at flights departing in the afternoon. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $679 on average. Flights to Washington, D.C. Dulles Intl Airport from Seattle at noon 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 $398 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 $317 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.

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

As of August 2025, prices for Seattle to Washington, D.C. Dulles Intl Airport flights are approximately 12% 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

$117

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 $117. The best round-trip flight deal from Seattle to Washington, D.C. Dulles Intl Airport found on momondo in the last 72 hours is $236.
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 56m.

  • 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
2,664 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $206Free CancellationRating
8.0
7,981 reviews
Search Delta flights
United AirlinesPriceFrom $237Free CancellationRating
7.4
8,925 reviews
Search United Airlines flights
American AirlinesPriceFrom $256Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
Alaska AirlinesPriceFrom $261Free CancellationRating
8.0
10,000 reviews
Search Alaska Airlines flights

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

    Across 7 Delta flights from Seattle to Washington, D.C. Dulles Intl Airport this week, the average price was $370, with the best Delta deals starting from $206 round-trip. 7,981 users have rated Delta on momondo, with an average score of 8.0/10.

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

    Alaska Airlines is also a popular choice for this route. Alaska Airlines flight deals for Seattle to Washington, D.C. Dulles Intl Airport start from as low as $261 round-trip, depending on your selected dates, with average Alaska Airlines deals seen on momondo around $413. Alaska Airlines operates 10 flights to Washington, D.C. Dulles Intl Airport from Seattle in an average week. Users have rated it 8.0/10 across 10,000 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
Gettysburg
Arlington
National Harbor
Winchester
Woodbridge
Tysons
Laurel
Silver Spring
Waldorf
Fredericksburg
Colonial Beach
Manassas
Harpers Ferry
Rockville
Towson
Gaithersburg
Fairfax
Reston
Glen Burnie

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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