What is the cheapest airline that flies from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl?

United Airlines, Alaska Airlines, and Delta are the most popular carriers operating from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl

What airlines fly to Washington, D.C. Dulles Intl Airport?

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Washington, D.C. Dulles Intl Airport from Seattle according to our data. Alaska Airlines is the first choice among our users, with 50% of people opting to fly with this airline when traveling to Washington, D.C. Dulles Intl Airport. Keep in mind that there are 5 different airlines that fly to Washington, D.C. Dulles Intl Airport on a routine basis, so you have a few additional options to choose from.

How many flights depart from Seattle to Washington, D.C. Dulles Intl Airport on average per day?

11 flights are operational daily from Seattle to Washington, D.C. Dulles Intl Airport as of September 2026. The most popular departure time for this route is 8:00AM, with 47% of flights per day taking off at noon.

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?

As of September 2026, there are 5 operators available to choose from 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.

$174 Cheap Flights from Seattle to Washington, D.C. Dulles Intl Airport in 2026

Q: How many flights depart from Seattle to Washington, D.C. Dulles Intl Airport on average per week?

81 flights are operational weekly from Seattle to Washington, D.C. Dulles Intl Airport as of September 2026. The most popular departure day for this route is Mon, with 26% of flights per week taking off on this day.

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Seattle to Washington, D.C.

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

9:45 pm - 6:20 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

29h 35m1 stop Las Vegas Harry Reid Intl

6:00 am - 9:42 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

30h 42m1 stop Las Vegas Harry Reid Intl

$298Frontier

Wed, Sep 23 - Sat, Sep 26

9:16 pm - 6:20 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

30h 04m1 stop Las Vegas Harry Reid Intl

6:00 am - 8:58 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

29h 58m1 stop Las Vegas Harry Reid Intl

$305Frontier

Mon, Oct 12 - Sat, Oct 17

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$345Alaska Airlines

Thu, Oct 1 - Wed, Oct 7

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

6:00 am - 8:58 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

29h 58m1 stop Las Vegas Harry Reid Intl

$353Multiple Airlines

Sat, Oct 17 - Wed, Oct 21

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$354Alaska Airlines

Tue, Oct 20 - Mon, Oct 26

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

6:00 am - 8:58 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

29h 58m1 stop Las Vegas Harry Reid Intl

$358Multiple Airlines

Thu, Oct 15 - Sat, Oct 17

2:52 pm - 10:56 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 04mnonstop

7:05 am - 9:56 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 51mnonstop

$376Delta

Thu, Oct 1 - Wed, Oct 7

8:25 am - 4:31 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 06mnonstop

1:05 pm - 3:51 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 46mnonstop

$377United Airlines

Mon, Oct 5 - Tue, Oct 13

8:09 am - 4:08 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

4h 59mnonstop

5:50 pm - 8:56 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

6h 06mnonstop

$377United Airlines

Fri, Nov 6 - Sun, Nov 8

11:58 am - 8:06 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 08mnonstop

7:05 am - 9:56 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 51mnonstop

$377Delta

Sat, Oct 10 - Tue, Oct 13

Cheap last minute flights

Enter your travel dates to find the best prices.

4:33 pm - 8:04 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

12h 31m1 stop Las Vegas Harry Reid Intl

6:00 am - 9:42 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

30h 42m1 stop Las Vegas Harry Reid Intl

$435Frontier

Thu, Sep 3 - Sun, Sep 13

4:33 pm - 8:04 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

12h 31m1 stop Las Vegas Harry Reid Intl

6:00 am - 6:28 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

15h 28m1 stop Las Vegas Harry Reid Intl

$437Frontier

Thu, Sep 3 - Mon, Oct 5

4:33 pm - 8:04 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

12h 31m1 stop Las Vegas Harry Reid Intl

5:33 pm - 8:24 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 51mnonstop

$459Multiple Airlines

Thu, Sep 3 - Mon, Oct 5

4:33 pm - 8:04 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

12h 31m1 stop Las Vegas Harry Reid Intl

7:00 am - 9:37 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 37mnonstop

$559Multiple Airlines

Thu, Sep 3 - Sun, Sep 13

11:04 pm - 7:07 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

10:35 am - 4:07 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

8h 32m1 stop Chicago O'Hare Intl

$603United Airlines

Sat, Sep 5 - Sun, Sep 6

11:04 pm - 7:07 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

10:35 am - 5:44 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

10h 09m2 stops Chicago O'Hare Intl Denver Intl

$662United Airlines

Sat, Sep 5 - Sun, Sep 6

9:35 pm - 5:40 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 05mnonstop

9:38 am - 12:20 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$772Alaska Airlines

Thu, Sep 3 - Mon, Oct 5

9:35 pm - 5:40 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 05mnonstop

7:00 am - 9:37 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 37mnonstop

$787Alaska Airlines

Thu, Sep 3 - Sun, Sep 13

8:38 am - 4:44 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 06mnonstop

6:14 am - 11:25 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

8h 11m1 stop Charlotte Douglas

$812American Airlines

Fri, Sep 4 - Mon, Sep 14

8:38 am - 4:44 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 06mnonstop

6:52 am - 2:51 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

10h 59m1 stop Dallas/Fort Worth

$812American Airlines

Thu, Sep 3 - Sun, Sep 13

Cheap direct flights

Enter your travel dates to find the best prices.

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$345Alaska Airlines

Thu, Oct 1 - Wed, Oct 7

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$354Alaska Airlines

Tue, Oct 20 - Mon, Oct 26

2:52 pm - 10:56 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 04mnonstop

7:05 am - 9:56 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 51mnonstop

$376Delta

Thu, Oct 1 - Wed, Oct 7

8:25 am - 4:31 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 06mnonstop

1:05 pm - 3:51 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 46mnonstop

$377United Airlines

Mon, Oct 5 - Tue, Oct 13

8:09 am - 4:08 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

4h 59mnonstop

5:50 pm - 8:56 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

6h 06mnonstop

$377United Airlines

Fri, Nov 6 - Sun, Nov 8

11:58 am - 8:06 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 08mnonstop

7:05 am - 9:56 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 51mnonstop

$377Delta

Sat, Oct 17 - Sat, Oct 24

9:35 pm - 5:40 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 05mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$484American Airlines

Thu, Oct 1 - Wed, Oct 7

3:56 pm - 11:59 pmSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 03mnonstop

7:02 am - 9:44 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$487American Airlines

Thu, Oct 22 - Sun, Oct 25

9:36 pm - 5:40 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 04mnonstop

9:38 am - 12:20 pmIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 42mnonstop

$524Multiple Airlines

Thu, Oct 22 - Wed, Oct 28

9:38 pm - 5:38 amSEA Seattle/Tacoma Intl-IAD Washington, D.C. Dulles Intl

5h 00mnonstop

7:00 am - 9:55 amIAD Washington, D.C. Dulles Intl-SEA Seattle/Tacoma Intl

5h 55mnonstop

$714Multiple Airlines

Sat, Dec 19 - Fri, Jan 1

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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

Oct 12

SEA9:16 pmSeattle/Tacoma Intl

30h 04m

1 stop

IAD6:20 amWashington, D.C. Dulles Intl

Oct 17

IAD6:00 amWashington, D.C. Dulles Intl

29h 58m

1 stop

SEA8:58 amSeattle/Tacoma Intl

$305

Frontier

Oct 12

SEA9:16 pmSeattle/Tacoma Intl

30h 04m

1 stop

IAD6:20 amWashington, D.C. Dulles Intl

Oct 17

IAD6:00 amWashington, D.C. Dulles Intl

29h 58m

1 stop

SEA8:58 amSeattle/Tacoma Intl

$307

Frontier

Sep 25

SEA9:45 pmSeattle/Tacoma Intl

29h 35m

1 stop

IAD6:20 amWashington, D.C. Dulles Intl

Sep 29

IAD6:00 amWashington, D.C. Dulles Intl

30h 42m

1 stop

SEA9:42 amSeattle/Tacoma Intl

$309

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

Our best Alaska Airlines deals on Seattle to Washington, D.C. Dulles Intl Airport flight tickets

Alaska Airlines

Oct 1

SEA3:56 pmSeattle/Tacoma Intl

5h 03m

IAD11:59 pmWashington, D.C. Dulles Intl

Oct 7

IAD7:02 amWashington, D.C. Dulles Intl

5h 42m

SEA9:44 amSeattle/Tacoma Intl

$345

Alaska Airlines

Oct 20

SEA3:56 pmSeattle/Tacoma Intl

5h 03m

IAD11:59 pmWashington, D.C. Dulles Intl

Oct 26

IAD7:02 amWashington, D.C. Dulles Intl

5h 42m

SEA9:44 amSeattle/Tacoma Intl

$354

Alaska Airlines

Oct 13

SEA3:56 pmSeattle/Tacoma Intl

5h 03m

IAD11:59 pmWashington, D.C. Dulles Intl

Oct 20

IAD7:02 amWashington, D.C. Dulles Intl

5h 42m

SEA9:44 amSeattle/Tacoma Intl

$367

momondo Fare Finder

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

Cheapest round-trip

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Wed 9/23

9:45 pm-6:20 am

1 stop29h 35m

Washington, D.C. Dulles Intl

Sat 9/26

6:00 am-9:42 am

1 stop30h 42m

$298

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Mon 10/12

9:16 pm-6:20 am

1 stop30h 04m

Washington, D.C. Dulles Intl

Sat 10/17

6:00 am-8:58 am

1 stop29h 58m

$305

Quickest round-trip

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Thu 10/1

3:56 pm-11:59 pm

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 10/7

7:02 am-9:44 am

Nonstop5h 42m

$345

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sat 10/17

3:56 pm-11:59 pm

Nonstop5h 03m

Washington, D.C. Dulles Intl

Wed 10/21

6:00 am-8:58 am

1 stop29h 58m

$353

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Tue 10/20

3:56 pm-11:59 pm

Nonstop5h 03m

Washington, D.C. Dulles Intl

Mon 10/26

7:02 am-9:44 am

Nonstop5h 42m

$354

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Thu 10/15

3:56 pm-11:59 pm

Nonstop5h 03m

Washington, D.C. Dulles Intl

Sat 10/17

6:00 am-8:58 am

1 stop29h 58m

$358

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Thu 10/1

2:52 pm-10:56 pm

Nonstop5h 04m

Washington, D.C. Dulles Intl

Wed 10/7

7:05 am-9:56 am

Nonstop5h 51m

$376

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Mon 10/5

8:25 am-4:31 pm

Nonstop5h 06m

Washington, D.C. Dulles Intl

Tue 10/13

1:05 pm-3:51 pm

Nonstop5h 46m

$377

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Fri 11/6

8:09 am-4:08 pm

Nonstop4h 59m

Washington, D.C. Dulles Intl

Sun 11/8

5:50 pm-8:56 pm

Nonstop6h 06m

$377

SeattleWashington, D.C.

SEA Seattle/Tacoma Intl - IAD Washington, D.C. Dulles Intl

SEAIAD

Seattle/Tacoma Intl

Sat 10/10

11:58 am-8:06 pm

Nonstop5h 08m

Washington, D.C. Dulles Intl

Tue 10/13

7:05 am-9:56 am

Nonstop5h 51m

$377

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Other information

What is the typical price of a round-trip flight between Seattle and Washington, D.C. Dulles Intl Airport?

Prices are currently typical for flights on this route.

Typical prices usually range from $285 to $572.
The lowest price recently found on this route was $298.

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 $309. 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 $349.

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 $449. When flying out on a Monday, 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 $617.

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 $372 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 $548 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 from Seattle 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 $444 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 $308 on momondo.

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

There are 4 cabin classes available to choose from on Seattle to Washington, D.C. Dulles Intl Airport 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 September 2026, prices for Seattle to Washington, D.C. Dulles Intl Airport flights are approximately 23% more expensive 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	$174
Fastest flight time	4h 50m
Direct flights	Every day

The best one-way flight to Washington, D.C. Dulles Intl Airport from Seattle in the past 72 hours is $174. The best round-trip flight deal from Seattle to Washington, D.C. Dulles Intl Airport found on momondo in the last 72 hours is $298.

The fastest flight from Seattle to Washington, D.C. Dulles Intl Airport takes 4h 50m

Direct flights go from Seattle to Washington, D.C. Dulles Intl Airport every day.

Search flight deals

Frequently asked questions about flying from Seattle to Washington, D.C. Dulles Intl Airport

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 50m.
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?
As of September 2026, there are 5 operators available to choose from 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?
Based on momondo bookings for flights between Seattle and Washington, D.C. Dulles Intl Airport, the leading plane model is Boeing 737, making up 22.49% of the total bookings. Other popular models include Boeing 737-800 Passenger/BBJ2 (winglets) with 20.70%, Boeing 737 MAX 9 with 19.35%, and Boeing 737 MAX 8 with 10.96%.
What is the most popular airline from Seattle to Washington, D.C. Dulles Intl Airport?
momondo data reveals that the most frequently booked airline on the route from Seattle to Washington, D.C. Dulles Intl Airport is Alaska Airlines, representing 49% of all bookings. The subsequent popular airlines are United Airlines at 36%, Delta at 13%, and American Airlines at 1%.

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
Delta	PriceFrom $147	Free Cancellation	Rating 7.8 8,544 reviews	Search Delta flights
American Airlines	PriceFrom $196	Free Cancellation	Rating 7.1 12,021 reviews	Search American Airlines flights
Alaska Airlines	PriceFrom $235	Free Cancellation	Rating 7.9 12,867 reviews	Search Alaska Airlines flights
United Airlines	PriceFrom $237	Free Cancellation	Rating 7.4 10,157 reviews	Search United Airlines flights
Frontier	PriceFrom $278	Free Cancellation	Rating 5.6 2,628 reviews	Search Frontier 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 $452, with the best Alaska Airlines deals starting from $235 round-trip. 12,867 users have rated Alaska Airlines on momondo, with an average score of 7.9/10.
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 $147 round-trip, depending on your selected dates, with average Delta deals seen on momondo around $302. Delta operates 7 flights to Washington, D.C. Dulles Intl Airport from Seattle in an average week. Users have rated it 7.8/10 across 8,544 reviews.

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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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Cheap flights from Seattle to Washington, D.C. from $174

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 10/20. 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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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

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

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

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

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

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

What is the cheapest airline that flies from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl?

What airlines fly to Washington, D.C. Dulles Intl Airport?

How many flights depart from Seattle to Washington, D.C. Dulles Intl Airport on average per day?

How many flights depart from Seattle to Washington, D.C. Dulles Intl Airport on average per week?

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

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

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Why use momondo?

An easier way to manage your Washington, D.C. Dulles Intl Airport trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to Washington, D.C.

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List of cabin classes available on flights landing in Washington, D.C.. Availability may vary depending on flight origin and airline.

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