Cheap flights from Washington, D.C. Dulles Intl Airport to Seattle from £108
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 16/8. 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
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 6 July 2025.
Round-trip from | £198 |
---|---|
One-way from | £108 |
Popular in | December |
Cheapest in | February |
Average price | £335 |
Find 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 6 July 2025.
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 6 July 2025.
Cheapflights Fare Finder
Customise your flight search to find flights from Dulles Intl to Seattle 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 858,174 searches. Data last updated 6 July 2025.
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
Tue 19/8
09:00-11:47
Nonstop5h 47m
Seattle/Tacoma Intl
Tue 26/8
23:30-07:32
Nonstop5h 02m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Sat 8/11
17:55-20:54
Nonstop5h 59m
Seattle/Tacoma Intl
Tue 11/11
09:25-21:06
1 stop8h 41m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Wed 13/8
07:35-10:20
Nonstop5h 45m
Seattle/Tacoma Intl
Mon 18/8
21:55-05:55
Nonstop5h 00m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Wed 13/8
08:10-16:54
1 stop11h 44m
Seattle/Tacoma Intl
Wed 13/8
19:05-06:50
1 stop8h 45m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Thu 21/8
12:48-22:43
1 stop12h 55m
Seattle/Tacoma Intl
Thu 28/8
23:55-12:33
1 stop9h 38m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Sat 23/8
15:50-22:30
1 stop9h 40m
Seattle/Tacoma Intl
Wed 27/8
06:45-22:05
2 stops12h 20m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Sat 16/8
08:10-16:54
1 stop11h 44m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Mon 11/8
07:35-10:20
Nonstop5h 45m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Fri 14/11
13:50-00:05
2 stops13h 15m
Washington, D.C.Seattle
IAD - SEA
IADSEA
Washington, D.C. Dulles Intl
Fri 3/10
18:30-17:01
1 stop25h 31m
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?
Use this chart to determine the optimal time to book a return flight from Dulles Intl to Seattle. Price data was last updated on 27 June 2025.
The best time to book flights from Washington, D.C. Dulles Intl Airport to Seattle is 66 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 £622). Flying from Washington, D.C. Dulles Intl Airport to Seattle in July is currently the most expensive (average of £946). 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?
Find hourly flight availability from Dulles Intl to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 6 July 2025.
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.
Weekly flight availability from Washington, D.C. Dulles Intl Airport to Seattle
Explore weekly flight availability from Dulles Intl to Seattle. 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 6 July 2025.
The most flights from IAD to SEA are scheduled on a Sunday (31 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (21 on average).
Reviews of airlines servicing Seattle
Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated 6 July 2025.
Read reviews from past customers who have flown with Alaska Airlines, Southwest, andDelta from Washington, D.C. Dulles Intl Airport to Seattle. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
Comfort
Crew
Overall
Boarding
Entertainment
Food
Reviews
Cheri,Jan 2025
FAT - SEA
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.
Travelling to a place near Washington, D.C. Dulles Intl Airport?
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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.