HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Dulles Intl

$144+ Cheap flights from Seattle (SEA) to Dulles Intl (IAD)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/20. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — IAD
Jan 22 — Jan 291
Wed 1/22
Wed 1/29
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Seattle to Dulles Intl with Cheapflights

1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”
2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.
3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

The best prices from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl are usually found in February or September, booked 52 days in advance, depart on a Tuesday or Wednesday and return on a Tuesday

Cheap flight deals from Seattle to Dulles Intl

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Dulles Intl (IAD). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated January 17, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$287
(Alaska Airlines)

One-way from

$144
(Delta)

Popular in

December

Cheapest in

February

Average price

$382
Provider with most accurate pricing for Seattle/Tacoma Intl-Washington, D.C. Dulles Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Washington, D.C. Dulles Intl flights.
Search Deals
From Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
Search Deals
One-way flight from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl
Search Deals
High demand for flights, 4% potential price rise
Search Deals
Best time to find cheap flights, 2% potential price drop
Search Deals
Average for round-trip flights in January 2025
Search Deals

Find flight deals from Seattle to Dulles Intl

Cheapest flights from Seattle to Dulles Intl
Explore the most affordable flight options available from Seattle to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 17, 2025.

This Alaska Airlines deal was found by Cheapflights users on 1/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/69:54 amSEA - IAD
Nonstop5h 03mAlaska Airlines
Sun 2/96:57 pmIAD - SEA
Nonstop6h 03mAlaska Airlines
Deal found 1/16$287
This United Airlines deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/57:00 amSEA - IAD
1 stop10h 40mUnited Airlines
Sun 2/95:30 pmIAD - SEA
Nonstop6h 01mUnited Airlines
Deal found 1/15$288
This American Airlines deal was found by Cheapflights users on 1/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/89:45 amSEA - IAD
1 stop9h 56mAmerican Airlines
Sat 2/155:13 pmIAD - SEA
1 stop9h 10mAmerican Airlines
Deal found 1/16$298
This Delta deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/127:10 amSEA - IAD
Nonstop5h 00mDelta
Tue 2/184:23 pmIAD - SEA
Nonstop6h 01mDelta
Deal found 1/15$307
This Cheapflightsfares deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/286:33 pmSEA - IAD
1 stop14h 14mSun Country Air
Fri 5/3012:45 pmIAD - SEA
1 stop13h 06mSun Country Air
Deal found 1/15$329
This Kissandfly.com deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/19:50 amSEA - IAD
Nonstop4h 58mMultiple Airlines
Sat 3/83:44 pmIAD - SEA
2 stops22h 18mMultiple Airlines
Deal found 1/15$353
This eDestinos deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/13:03 pmSEA - IAD
2 stops22h 23mFrontier
Sat 3/83:44 pmIAD - SEA
2 stops46h 18mFrontier
Deal found 1/15$365
This Southwest deal was found by Cheapflights users on 1/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/196:40 amSEA - IAD
2 stops13h 45mSouthwest
Mon 3/243:35 pmIAD - SEA
1 stop12h 15mSouthwest
Deal found 1/15$452

Find flights from Seattle to Dulles Intl within your budget

Customize your flight search to find flights from Seattle to Dulles Intl 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, Cheapflights users made 2,558,603 searches. Data last updated January 17, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Thu 2/6

9:54 am-5:57 pm

Nonstop5h 03m

Washington, D.C. Dulles Intl

Mon 2/10

6:57 pm-10:00 pm

Nonstop6h 03m

$287

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 2/5

7:00 am-8:40 pm

1 stop10h 40m

Washington, D.C. Dulles Intl

Sun 2/9

5:30 pm-8:31 pm

Nonstop6h 01m

$288

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 2/8

9:45 am-10:41 pm

1 stop9h 56m

Washington, D.C. Dulles Intl

Sat 2/15

5:13 pm-11:23 pm

1 stop9h 10m

$298

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 2/12

7:10 am-3:10 pm

Nonstop5h 00m

Washington, D.C. Dulles Intl

Tue 2/18

4:23 pm-7:24 pm

Nonstop6h 01m

$307

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 5/28

6:33 pm-11:47 am

1 stop14h 14m

Washington, D.C. Dulles Intl

Fri 5/30

12:45 pm-10:51 pm

1 stop13h 06m

$329

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 3/1

9:50 am-5:48 pm

Nonstop4h 58m

Washington, D.C. Dulles Intl

Sat 3/8

3:44 pm-11:02 am

2 stops22h 18m

$353

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Sat 3/1

3:03 pm-4:26 pm

2 stops22h 23m

Washington, D.C. Dulles Intl

Sat 3/8

3:44 pm-11:02 am

2 stops46h 18m

$365

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Wed 3/19

6:40 am-11:25 pm

2 stops13h 45m

Washington, D.C. Dulles Intl

Mon 3/24

3:35 pm-12:50 am

1 stop12h 15m

$452

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Fri 2/7

9:54 am-5:57 pm

Nonstop5h 03m

$144

SeattleWashington, D.C.

SEA - IAD

SEAIAD

Seattle/Tacoma Intl

Tue 4/22

11:59 pm-11:30 am

1 stop8h 31m

$149

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/16

Showing 1-10 of 16 results
1
2

Compare providers for flights from Seattle to Dulles Intl

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Dulles Intl in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy2 starsTrust Score*3 stars
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
KAYAKPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Washington, D.C. Dulles Intl Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Washington, D.C. Dulles Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Seattle to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Seattle to Dulles Intl

Get recent, data-driven insights about flights from Seattle to Dulles Intl including ideal travel times, pricing trends, and more.

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

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Dulles Intl. Price data was last updated on January 10, 2025.

Booking 34 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Washington, D.C. Dulles Intl Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

Currently, August is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $389). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to IAD?

Find hourly flight availability from Seattle to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated January 17, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 22% on your trip compared to booking a flight at noon.

What is the cheapest day to fly from Seattle to Washington, D.C. Dulles Intl Airport?

Use this chart to determine the cheapest time to fly round-trip from Seattle to Dulles Intl. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Seattle to Washington, D.C. Dulles Intl Airport flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Saturday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Seattle to Washington, D.C. Dulles Intl Airport

Explore weekly flight availability from Seattle to Dulles Intl. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated January 17, 2025.

The most flights from SEA to IAD are scheduled on a Thursday (16 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (6 on average).

Rainfall in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport ranges from 2.6 - 4.0 inches per month. May is typically the wettest month, when rainfall can reach 4.0 in. February is typically the driest time to visit Washington, D.C. Dulles Intl Airport when rainfall is around 2.6 in.

Temperature in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 35.6 F).

Reviews of airlines servicing Dulles Intl

Get insights into the airlines that provide service to Dulles Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Dulles Intl. Reviews last updated January 17, 2025.
Get a feel of what it's like to fly with American Airlines, United Airlines and Delta from Seattle to Washington, D.C. by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Southwest
8.1
Very good
4,659 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Alaska Airlines
8.0
Very good
9,681 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Delta
8.0
Very good
8,511 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

United Airlines
7.4
Good
8,965 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,659 reviews

Food

7.2

Crew

8.7

Comfort

8.1

Entertainment

7.7

Boarding

8.2

Overall

8.1

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Dulles Intl. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to Washington, D.C. Dulles Intl?

    If you book a flight to Washington, D.C. Dulles Intl from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 10 flights from Seattle/Tacoma Intl to Washington, D.C. Dulles Intl per day from 5 different airlines.

  • What are the cheapest airlines flying from Seattle to Washington, D.C. Dulles Intl Airport round-trip?

    Alaska Airlines, at $287, was found to be the cheapest airline from Seattle to Washington, D.C. Dulles Intl Airport.Alternate airlines to your destination round-trip include United Airlines and American Airlines. Alaska Airlines is 29% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Seattle to Washington, D.C. Dulles Intl Airport one-way?

    The cheapest airlines for a one-way flight from Seattle to Washington, D.C. Dulles Intl Airport are Delta ($144), United Airlines ($149), and Frontier ($151).

  • What are the most reliable airlines from Seattle to Washington, D.C. Dulles Intl Airport?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to Washington, D.C. Dulles Intl Airport on time: Copa Airlines (89%), Korean Air (88%), Brussels Airlines (88%).

  • What are the cheapest flights from Seattle to Washington, D.C. Dulles Intl Airport?

    Looking at all options, your cheapest flight can be booked for $138. While the most popular route (Seattle/Tacoma Intl - Washington, D.C. Dulles Intl) can be booked for $273 on average our data indicates $1,108 when flying from Seattle to Washington, D.C. Dulles Intl Airport.

  • Can I find deals for flights from Seattle to Dulles Intl that include hotel bookings?

    Yes. In addition to deals on Seattle to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Dulles Intl?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Dulles Intl.

  • Can I find deals for business class flights from Seattle to Dulles Intl?

    Yes. Cheapflights offers flight deals from Seattle to Dulles Intl by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Washington, D.C. Dulles Intl Airport?

    Currently, August is the cheapest month in which you can book a flight from Seattle to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Seattle to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $389). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Fairfax
Arlington
Alexandria
Springfield
Silver Spring
Rockville
Tysons
Gaithersburg
Fredericksburg
Linthicum Heights
Laurel
Falls Church
Greenbelt
Sterling
Easton
Oxon Hill
Herndon
Woodbridge
Bowie
Reston

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Seattle to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.
Seattle to Reagan-National flights
Seattle to Baltimore flights
Portland to Dulles Intl flights
Portland to Reagan-National flights
Portland to Baltimore flights
Spokane to Dulles Intl flights
Spokane to Reagan-National flights
Spokane to Baltimore flights
Pasco to Dulles Intl flights
Pasco to Reagan-National flights
Pasco to Baltimore flights
Pullman to Dulles Intl flights
Pullman to Baltimore flights
Pullman to Reagan-National flights
Walla Walla to Baltimore flights
Wenatchee to Baltimore flights
Bellingham to Dulles Intl flights
Walla Walla to Dulles Intl flights
Bellingham to Reagan-National flights
Yakima to Baltimore flights
Bellingham to Baltimore flights
Walla Walla to Reagan-National flights
Wenatchee to Dulles Intl flights
Wenatchee to Reagan-National flights
Yakima to Reagan-National flights
Yakima to Dulles Intl flights

Top 5 airlines flying from Seattle to Dulles Intl

Discover the top 5 airlines that operate flights from Seattle to Dulles Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated January 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
Sun Country AirCheapest$169Average$534FlexibilityNo cancel feeOn-time83%
DeltaCheapest$199Average$411FlexibilityNo cancel feeOn-timeN/A
Alaska AirlinesCheapest$235Average$427FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$240Average$448FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$337Average$532FlexibilityNo cancel feeOn-time71%
100% Free
Cheapflights is completely free to use, so you can start saving the moment you arrive.
Book with Flexibility
Our users can plan ahead with confidence and find flights with no change fees
Travel Smart
Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.