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฿5,525 Cheap Flights from Washington (IAD) to Seattle (SEA)

View ฿5,525 flight on Sat, 26 Sept 2026Opens in a new window

Popular airlines from Washington Dulles International Airport (IAD) to Seattle-Tacoma International Airport (SEA)

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Cheap Flights from Washington (IAD) to Seattle (SEA)

Prices were available within the past 7 days and start at ฿5,525 for one-way flights and ฿10,915 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿10,915 Return, found 3 days ago
฿10,915
Return
found 3 days ago
Select Delta flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿10,915 found 3 days ago
American Airlines
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿13,800 Return, found 3 days ago
฿13,800
Return
found 3 days ago
Select American Airlines flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿13,800 found 3 days ago
Delta
Sun, 6 Sept - Tue, 8 Sept
IAD
Washington
SEA
Seattle
฿14,135 Return, found 3 days ago
฿14,135
Return
found 3 days ago
Select Delta flight, departing Sun, 6 Sept from Washington to Seattle, returning Tue, 8 Sept, priced at ฿14,135 found 3 days ago
Delta
Sun, 6 Sept - Tue, 8 Sept
IAD
Washington
SEA
Seattle
฿14,140 Return, found 3 days ago
฿14,140
Return
found 3 days ago
Select Delta flight, departing Sun, 6 Sept from Washington to Seattle, returning Tue, 8 Sept, priced at ฿14,140 found 3 days ago
United
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿14,145 Return, found 3 days ago
฿14,145
Return
found 3 days ago
Select United flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿14,145 found 3 days ago
Delta
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿14,310 Return, found 3 days ago
฿14,310
Return
found 3 days ago
Select Delta flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿14,310 found 3 days ago
Delta
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿14,315 Return, found 3 days ago
฿14,315
Return
found 3 days ago
Select Delta flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿14,315 found 3 days ago
Delta
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿14,475 Return, found 3 days ago
฿14,475
Return
found 3 days ago
Select Delta flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿14,475 found 3 days ago
United
Tue, 22 Sept - Fri, 9 Oct
IAD
Washington
SEA
Seattle
฿14,480 Return, found 3 days ago
฿14,480
Return
found 3 days ago
Select United flight, departing Tue, 22 Sept from Washington to Seattle, returning Fri, 9 Oct, priced at ฿14,480 found 3 days ago
United
Thu, 17 Sept - Wed, 23 Sept
IAD
Washington
SEA
Seattle
฿14,630 Return, found 2 hours ago
฿14,630
Return
found 2 hours ago
Select United flight, departing Thu, 17 Sept from Washington to Seattle, returning Wed, 23 Sept, priced at ฿14,630 found 2 hours ago

Find the cheapest month to fly from Washington (IAD) to Seattle (SEA)

September is typically the cheapest month to fly

From ฿8,421 - ฿10,853 per traveller.

Frequently asked questions

How much is a flight from Washington Dulles Intl. Airport (IAD) to Seattle - Tacoma Intl. Airport (SEA)?
Start packing your bags, because round-trip flights from IAD to Sea-Tac Airport start from ฿10,915. That's based on fares advertised within the last 7 days on Expedia for flights departing within the next year. Prices can change quickly, so book today to get the best deal. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from IAD to Sea-Tac Airport?
Most flights can be conveniently cancelled online, but whether you incur a fee differs between airlines. If you do need to cancel your holiday, follow the instructions in the Customer Service Portal.
How do I find cheap flights from Dulles Intl. Airport to Seattle - Tacoma Intl. Airport (SEA) that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for Dulles Intl. Airport to Seattle - Tacoma Intl. Airport (SEA) flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Dulles Intl. Airport to Seattle - Tacoma Intl. Airport (SEA)?
You'll be in the air for a while, as the flight distance between Chantilly and SeaTac is 3,700 kilometres. Set up a playlist of your favourite songs before leaving home to keep yourself entertained during your trip.
Which airlines fly direct from Washington Dulles Intl. Airport (IAD) to SEA?
United Airlines (UA) is a popular option. It offers 60 flights from IAD to Sea-Tac Airport each month. Offering 56 flights a month along this route, Alaska Airlines (AS) is another top pick.
Are IAD to Sea-Tac Airport flight tickets cheaper when they're purchased at the last minute?
It is possible to find a fantastic last-minute deal from IAD to Seattle - Tacoma Intl. Airport (SEA), but it can also be hit-or-miss. As many airlines release seats up to 12 months in advance, it's worthwhile keeping an eye on fares early and being ready to pounce when you see a good bargain. Expedia compares air carrier prices and updates flight deals frequently, so you can rest assured you're always seeing the latest offers.

Travel information

Origin airport
Washington Dulles Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
American Airlines, Delta, United
Return price
฿10,915
Distance
3679 km
Average flight time
3 hours 11 mins

Book with confidence

Perfect flights from Washington to Seattle

Embark on an unforgettable journey without breaking the bank with Expedia's incredible deals on cheap flights from Washington to Seattle. Whether you're aching for a romantic escape with your partner, craving an adventurous solo expedition, or yearning to immerse yourself in the local history and culture, we've got you covered.
 
Picture yourself strolling through the streets of , surrounded by breathtaking architecture and absorbing the vibrant atmosphere of this captivating city. Indulge in the mouth-watering local specialties, from tantalizing street food to exquisite fine dining. With Expedia, you can experience all of this and more, without sacrificing your budget.
 
Our flexible Washington Dulles Intl. to Seattle - Tacoma Intl. ticket options cater to your travel preferences, with incredible one-way fares from ฿5,525 and roundtrip prices from ฿10,915. Whether you're planning a short city break or a longer adventure, our dynamic pricing ensures that you find the best deals for your journey.
 
But the magic doesn't stop there. Expedia offers a range of partner services to enhance your trip. Rent a car at Seattle - Tacoma Intl. and explore and its surrounding areas at your own pace. Discover hidden gems off the beaten path, and create unforgettable memories. We also provide a handpicked selection of accommodations, from charming bed and breakfasts to luxury hotels, ensuring that you have a comfortable and memorable stay.
 
Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support are designed to make your travel experience seamless and stress-free. So, why wait? Book your to travel arrangements today and embark on the journey of a lifetime in Seattle.
Perfect flights from Washington to Seattle
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