Cheap flights from Washington, D.C. Dulles Intl Airport to Seattle from £158
This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/11. Fares are subject to change and may not be available on all flights or dates of travel.
Cheap flight deals from Dulles Intl to Seattle
Cheapest flights from Dulles Intl to SeattleExplore the most affordable flight options available from Dulles Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 13 October 2026.
Explore the most affordable flight options available from Dulles Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 13 October 2026.
Best flights from Dulles Intl to SeattleDiscover carefully curated flight deals from Dulles Intl to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 13 October 2026.
Discover carefully curated flight deals from Dulles Intl to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 13 October 2026.
Direct flights from Dulles Intl to SeattleExplore direct flight options from Dulles Intl to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 13 October 2026.
Explore direct flight options from Dulles Intl to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 13 October 2026.
Last-minute flights from Dulles Intl to SeattleDiscover last-minute flight deals from Dulles Intl to Seattle. Data last updated 13 October 2026 and is based on user searches.
Discover last-minute flight deals from Dulles Intl to Seattle. Data last updated 13 October 2026 and is based on user searches.
One-way flights from Dulles Intl to SeattleSearch for one-way flight options from Dulles Intl to Seattle. Find affordable one-way fares based on user searches. Data last updated 13 October 2026.
Search for one-way flight options from Dulles Intl to Seattle. Find affordable one-way fares based on user searches. Data last updated 13 October 2026.
Find flight deals from Dulles Intl to Seattle
Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to Seattle (SEA). 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 13 October 2026.
Cheapflights 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
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Sat 9/1
07:05-10:05
Nonstop6h 00m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Mon 14/12
17:18-20:27
Nonstop6h 09m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Tue 8/12
07:00-10:05
Nonstop6h 05m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Wed 6/1
17:30-20:33
Nonstop6h 03m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Sat 9/1
15:15-21:59
1 stop9h 44m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Wed 11/11
14:05-21:19
1 stop10h 14m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Sat 30/1
08:22-21:17
2 stops15h 55m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Tue 24/11
18:39-09:29
1 stop17h 50m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Thu 25/3
07:05-10:05
Nonstop6h 00m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Washington, D.C.Seattle
IAD Washington, D.C. Dulles Intl - SEA Seattle/Tacoma Intl
IADSEA
Washington, D.C. Dulles Intl
Fri 15/1
07:05-10:05
Nonstop6h 00m
Seattle/Tacoma Intl
Wed 31/12
00:00-03:00
Nonstop0h 00m
Best time to book a flight from Dulles Intl to Seattle
Have a flexible travel schedule? Discover the best time to fly to Seattle from Dulles Intl with our price prediction graph.
Cheapflights Insights
Everything you need to know about your flight from Washington, D.C. Dulles Intl Airport to Seattle
How far ahead should I book a flight from Washington, D.C. Dulles Intl Airport to Seattle?
The best time to book flights from Washington, D.C. Dulles Intl Airport to Seattle is 54 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Seattle?
Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Seattle (average of £174). Flying from Washington, D.C. Dulles Intl Airport to Seattle in June is currently the most expensive (average of £409). 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 IAD to SEA?
When flying from Washington, D.C. Dulles Intl Airport to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
Related info for your journey
Find useful and relevant information for your journey from Dulles Intl to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Direct flights to Washington
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Dulles Intl and Seattle flights
Browse other Dulles Intl and Seattle flight options. Last updated on 13 October 2026.
Other flights from Dulles Intl
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Popular flight searches
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Other flights to Seattle
Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 13 October 2026.
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How does Cheapflights help users find flights from Dulles Intl to Seattle?
When you search for this flight from Dulles Intl to Seattle, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.
Why should you use Cheapflights to find cheap flight tickets from Dulles Intl to Seattle?
Cheapflights simply makes it quick and affordable to book flights from Dulles Intl to Seattle by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.
Can Cheapflights find flights from Dulles Intl to Seattle with no change fees?
Need flexible booking options for your flight to Seattle from Dulles Intl? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.
Can Cheapflights notify me if prices for flights from Dulles Intl to Seattle become cheaper?
Yes, Cheapflights offers price alerts on Dulles Intl to Seattle flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.