What airlines fly to Seattle?

Alaska Airlines, United Airlines and Delta are the top three most popular airlines that fly to Seattle from Washington, D.C. Dulles Intl Airport according to our data. Alaska Airlines is the first choice among our users, with 43% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 6 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

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

As of February 2026, 17 flights take off from Washington, D.C. Dulles Intl Airport and land in Seattle each day. The most common flight departure time for this route is 7:00AM, with 52% of daily flights taking off at noon.

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

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

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

Prices for flights from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport are updated daily.

What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

The travel and health documents required for your trip to Seattle/Tacoma 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 Seattle/Tacoma Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

$129 Cheap Flights from Washington, D.C. Dulles Intl Airport to Seattle in 2026

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

As of February 2026, there are 120 flights per week flying from Washington, D.C. Dulles Intl Airport to Seattle. The most common day of the week flights depart is Thu, with 18% of flights taking off on this day.

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

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

7:00 am - 10:03 am

IAD

SEA

6h 03mnonstop

3:55 pm - 11:49 pm

SEA

IAD

4h 54mnonstop

$197Delta

Thu, Mar 19 - Tue, Mar 24

7:10 am - 9:56 am

IAD

SEA

5h 46mnonstop

11:59 pm - 11:18 am

SEA

IAD

8h 19m

1 stop

$207Delta

Thu, May 7 - Wed, May 13

5:55 pm - 8:56 pm

IAD

SEA

6h 01mnonstop

8:00 am - 4:11 pm

SEA

IAD

5h 11mnonstop

$210United Airlines

Tue, Mar 24 - Tue, Mar 31

7:10 am - 9:58 am

IAD

SEA

5h 48mnonstop

9:41 pm - 5:50 am

SEA

IAD

5h 09mnonstop

$217Alaska Airlines

Thu, Apr 23 - Wed, Apr 29

4:30 pm - 10:30 pm

IAD

SEA

9h 00m

1 stop

8:10 am - 12:20 am

SEA

IAD

13h 10m

1 stop

$222Southwest

Tue, Apr 14 - Fri, Apr 17

6:47 pm - 9:26 am

IAD

SEA

17h 39m

1 stop

9:41 pm - 5:50 am

SEA

IAD

5h 09mnonstop

$227Alaska Airlines

Thu, Apr 23 - Wed, Apr 29

5:55 pm - 8:53 pm

IAD

SEA

5h 58mnonstop

11:14 pm - 7:23 am

SEA

IAD

5h 09mnonstop

$231United Airlines

Fri, May 8 - Sat, May 16

5:55 pm - 8:53 pm

IAD

SEA

5h 58mnonstop

7:05 pm - 6:58 am

SEA

IAD

8h 53m

1 stop

$233United Airlines

Thu, May 7 - Tue, May 26

7:10 am - 9:58 am

IAD

SEA

5h 48mnonstop

3:53 pm - 11:59 pm

SEA

IAD

5h 06mnonstop

$237Alaska Airlines

Tue, May 5 - Thu, May 14

5:55 pm - 8:56 pm

IAD

SEA

6h 01mnonstop

7:00 am - 7:23 pm

SEA

IAD

9h 23m

1 stop

$240United Airlines

Tue, Mar 24 - Wed, Apr 1

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

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

American Airlines

Mar 25

IAD5:00 amWashington, D.C. Dulles Intl

10h 51m

1 stop

SEA12:51 pmSeattle/Tacoma Intl

Mar 30

SEA10:08 pmSeattle/Tacoma Intl

9h 52m

1 stop

IAD11:00 amWashington, D.C. Dulles Intl

$262

American Airlines

Mar 2

IAD2:03 pmWashington, D.C. Dulles Intl

8h 11m

1 stop

SEA7:14 pmSeattle/Tacoma Intl

Mar 6

SEA10:08 pmSeattle/Tacoma Intl

7h 40m

1 stop

IAD8:48 amWashington, D.C. Dulles Intl

$616

American Airlines

Mar 2

IAD7:05 amWashington, D.C. Dulles Intl

6h 00m

SEA10:05 amSeattle/Tacoma Intl

Mar 6

SEA10:08 pmSeattle/Tacoma Intl

7h 40m

1 stop

IAD8:48 amWashington, D.C. Dulles Intl

$632

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

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

United Airlines

Mar 24

IAD5:55 pmWashington, D.C. Dulles Intl

6h 01m

SEA8:56 pmSeattle/Tacoma Intl

Mar 31

SEA8:00 amSeattle/Tacoma Intl

5h 11m

IAD4:11 pmWashington, D.C. Dulles Intl

$210

United Airlines

May 8

IAD5:55 pmWashington, D.C. Dulles Intl

5h 58m

SEA8:53 pmSeattle/Tacoma Intl

May 16

SEA11:14 pmSeattle/Tacoma Intl

5h 09m

IAD7:23 amWashington, D.C. Dulles Intl

$231

United Airlines

May 7

IAD5:55 pmWashington, D.C. Dulles Intl

5h 58m

SEA8:53 pmSeattle/Tacoma Intl

May 26

SEA7:05 pmSeattle/Tacoma Intl

8h 53m

1 stop

IAD6:58 amWashington, D.C. Dulles Intl

$233

momondo Fare Finder

Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 3/19

7:00 am-10:03 am

Nonstop6h 03m

Seattle/Tacoma Intl

Tue 3/24

3:55 pm-11:49 pm

Nonstop4h 54m

$197

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 5/7

7:10 am-9:56 am

Nonstop5h 46m

Seattle/Tacoma Intl

Wed 5/13

11:59 pm-11:18 am

1 stop8h 19m

$207

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 3/24

5:55 pm-8:56 pm

Nonstop6h 01m

Seattle/Tacoma Intl

Tue 3/31

8:00 am-4:11 pm

Nonstop5h 11m

$210

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 4/23

7:10 am-9:58 am

Nonstop5h 48m

Seattle/Tacoma Intl

Wed 4/29

9:41 pm-5:50 am

Nonstop5h 09m

$217

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 4/14

4:30 pm-10:30 pm

1 stop9h 00m

Seattle/Tacoma Intl

Fri 4/17

8:10 am-12:20 am

1 stop13h 10m

$222

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 4/23

6:47 pm-9:26 am

1 stop17h 39m

Seattle/Tacoma Intl

Wed 4/29

9:41 pm-5:50 am

Nonstop5h 09m

$227

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Fri 5/8

5:55 pm-8:53 pm

Nonstop5h 58m

Seattle/Tacoma Intl

Sat 5/16

11:14 pm-7:23 am

Nonstop5h 09m

$231

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 5/7

5:55 pm-8:53 pm

Nonstop5h 58m

Seattle/Tacoma Intl

Tue 5/26

7:05 pm-6:58 am

1 stop8h 53m

$233

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 5/5

7:10 am-9:58 am

Nonstop5h 48m

Seattle/Tacoma Intl

Thu 5/14

3:53 pm-11:59 pm

Nonstop5h 06m

$237

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 3/24

5:55 pm-8:56 pm

Nonstop6h 01m

Seattle/Tacoma Intl

Wed 4/1

7:00 am-7:23 pm

1 stop9h 23m

$240

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Showing 1-10 of 20 resultsSorted by cheapest first

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

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 cheapest month to fly to Seattle?

In general, January is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $231. If you don’t want to visit Seattle in January, then you should wait until February to fly from Washington, D.C. Dulles Intl Airport, when ticket prices are also cheap, with an average price of $299.

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Washington, D.C. Dulles Intl Airport is on a Tuesday. momondo users have found tickets for Tuesday departures for as low as $436. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday is the most expensive day to depart from Washington, D.C. Dulles Intl Airport because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $566.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Washington, D.C. Dulles Intl Airport in the evening is the least expensive time of day to depart. momondo users have found prices as low as $436 when looking at flights departing in the evening. Flights to Seattle are more costly in the morning, with an average ticket price of $493. Departure times in the morning fall within the peak daily travel times, which is why tickets can be more expensive.

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

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

How far in advance should I book a flight to Seattle?

You are more likely to see cheaper flights to Seattle from Washington, D.C. Dulles Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $379 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Washington, D.C. Dulles Intl Airport for as low as $309 on momondo.

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

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

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

As of February 2026, prices for Washington, D.C. Dulles Intl Airport to Seattle flights are approximately 6% more expensive when compared to flights at the same time last year.

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

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

Estimated round-trip price

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

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

Best Price Found	$193
Fastest flight time	5h 35m
Direct flights	Every day
Airports in Seattle	1 airport

The best one-way flight to Seattle from Washington, D.C. Dulles Intl Airport in the past 72 hours is $193. The best round-trip flight deal from Washington, D.C. Dulles Intl Airport to Seattle found on momondo in the last 72 hours is $342.

The fastest flight from Washington, D.C. Dulles Intl Airport to Seattle takes 5h 35m

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

There is 1 airport in Seattle. From Washington, D.C. Dulles Intl Airport there are direct flights to Seattle/Tacoma Intl (SEA).

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How far is Washington, D.C. Dulles Intl to Seattle/Tacoma Intl by plane?
The distance between Washington, D.C. Dulles Intl and Seattle/Tacoma Intl is about 2299.7 mi. A reasonable flight in good conditions will take 5h 35m.
When did momondo last update prices for flights from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport?
Prices for flights from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport are updated daily.
How many operators does momondo search for flights from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport?
There are 6 operators available for flights from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport as of February 2026.
How old do you have to be to fly from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Washington, D.C. Dulles Intl Airport to Seattle/Tacoma Intl Airport.
What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?
The travel and health documents required for your trip to Seattle/Tacoma 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 Seattle/Tacoma 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 Washington, D.C. Dulles Intl Airport to Seattle?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Washington, D.C. Dulles Intl Airport to Seattle is Boeing 737 (20.34% of total bookings). The next most popular plane models are Boeing 737-800 Passenger/BBJ2 (winglets) (16.82%), Boeing 737-900 (14.63%), and Boeing 737 MAX 8 (12.46%).
What is the most popular airline from Washington, D.C. Dulles Intl Airport to Seattle?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Washington, D.C. Dulles Intl Airport to Seattle is Alaska Airlines (41% of total bookings). The next most popular airlines are United Airlines (30%), Delta (16%), and Hawaiian Airlines (7%).

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

Compare and see reviews for airlines that fly from Washington, D.C. Dulles Intl Airport to Seattle with momondo

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $111	Free Cancellation	Rating 5.7 3,045 reviews	Search Frontier flights
Hawaiian Airlines	PriceFrom $143	Free Cancellation	Rating 7.8 2,835 reviews	Search Hawaiian Airlines flights
Delta	PriceFrom $144	Free Cancellation	Rating 7.9 8,238 reviews	Search Delta flights
United Airlines	PriceFrom $211	Free Cancellation	Rating 7.4 9,341 reviews	Search United Airlines flights
Alaska Airlines	PriceFrom $236	Free Cancellation	Rating 8.0 11,923 reviews	Search Alaska Airlines flights
American Airlines	PriceFrom $336	Free Cancellation	Rating 7.2 11,336 reviews	Search American Airlines flights

Alaska Airlines Flights From Washington, D.C. Dulles Intl Airport to Seattle
Across 6 Alaska Airlines flights from Washington, D.C. Dulles Intl Airport to Seattle this week, the average price was $422, with the best Alaska Airlines deals starting from $236 round-trip. 11,923 users have rated Alaska Airlines on momondo, with an average score of 8.0/10.
Delta Flights From Washington, D.C. Dulles Intl Airport to Seattle
The best Delta deal for Washington, D.C. Dulles Intl Airport to Seattle flight tickets found on momondo in the last 72 hours was $144, round-trip. It should be noted that an average Delta flight deal for this route in this time was higher, at $347 round-trip. Delta operates 7 flights out of Washington, D.C. Dulles Intl Airport into Seattle in an average week, so prices vary by time and availability. 8,238 Delta reviews by users on momondo have scored the airline at 7.9/10.

Tacoma

Leavenworth

SeaTac

Ocean Shores

Renton

Olympia

Lynnwood

Kent

Marysville

Redmond

Puyallup

Cle Elum

Lakewood

Tukwila

Federal Way

Kirkland

Fife

Westport

Centralia

Tumwater

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Washington, D.C. to Seattle for you.

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

Yes. momondo allows you to filter the results for Washington, D.C. to Seattle flights to just show those with flexible booking policies.

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

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 Washington, D.C. to Seattle.

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

Price alerts on flights to Seattle from Washington, D.C. are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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Airports servicing Washington

Walla Walla Airport

Bellingham Airport

Wenatchee Pangborn Field Airport

Eastsound Orcas Island Airport

Friday Harbor SPB Airport

Spokane Airport

Kenmore Air Harbor Airport

Pasco Tri Cities Airport

Pullman Moscow Regional Airport

Rosario SPB Airport

Yakima Air Terminal Airport

Cheap flights from Washington, D.C. Dulles Intl Airport to Seattle from $129

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

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

What is the cheapest month to fly to Seattle?

What is the cheapest day to depart on your flight to Seattle?

What is the cheapest time of day to depart on your flight to Seattle?

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

How far in advance should I book a flight to Seattle?

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

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

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

What airlines fly to Seattle?

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

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

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

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

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

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Fastest flight time

Direct flights

Airports in Seattle

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

Compare and see reviews for airlines that fly from Washington, D.C. Dulles Intl Airport to Seattle with momondo

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

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

Traveling to a place near Seattle?

Why use momondo?

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

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

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

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

An easier way to manage your Seattle 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.

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List of cabin classes available on flights landing in Seattle. Availability may vary depending on flight origin and airline.

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