฿4,840 Cheap Flights from Washington (IAD) to Seattle (SEA)

View ฿4,840 flight on Sun, 16 Aug 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 ฿4,840 for one-way flights and ฿18,050 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Tue, 30 Jun - Mon, 6 Jul
IAD
Washington
SEA
Seattle
฿18,050 Return, found 6 days ago
฿18,050
Return
found 6 days ago
Select American Airlines flight, departing Tue, 30 Jun from Washington to Seattle, returning Mon, 6 Jul, priced at ฿18,050 found 6 days ago
Delta
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿18,380 Return, found 6 days ago
฿18,380
Return
found 6 days ago
Select Delta flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿18,380 found 6 days ago
American Airlines
Tue, 30 Jun - Mon, 6 Jul
IAD
Washington
SEA
Seattle
฿18,705 Return, found 6 days ago
฿18,705
Return
found 6 days ago
Select American Airlines flight, departing Tue, 30 Jun from Washington to Seattle, returning Mon, 6 Jul, priced at ฿18,705 found 6 days ago
American Airlines
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿18,740 Return, found 6 days ago
฿18,740
Return
found 6 days ago
Select American Airlines flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿18,740 found 6 days ago
American Airlines
Tue, 30 Jun - Mon, 6 Jul
IAD
Washington
SEA
Seattle
฿19,040 Return, found 6 days ago
฿19,040
Return
found 6 days ago
Select American Airlines flight, departing Tue, 30 Jun from Washington to Seattle, returning Mon, 6 Jul, priced at ฿19,040 found 6 days ago
United
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿19,200 Return, found 6 days ago
฿19,200
Return
found 6 days ago
Select United flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿19,200 found 6 days ago
United
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿19,360 Return, found 6 days ago
฿19,360
Return
found 6 days ago
Select United flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿19,360 found 6 days ago
American Airlines
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿19,530 Return, found 6 days ago
฿19,530
Return
found 6 days ago
Select American Airlines flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿19,530 found 6 days ago
United
Wed, 1 Jul - Tue, 7 Jul
IAD
Washington
SEA
Seattle
฿19,685 Return, found 6 days ago
฿19,685
Return
found 6 days ago
Select United flight, departing Wed, 1 Jul from Washington to Seattle, returning Tue, 7 Jul, priced at ฿19,685 found 6 days ago
United
Mon, 6 Jul - Mon, 20 Jul
IAD
Washington
SEA
Seattle
฿19,785 Return, found 2 hours ago
฿19,785
Return
found 2 hours ago
Select United flight, departing Mon, 6 Jul from Washington to Seattle, returning Mon, 20 Jul, priced at ฿19,785 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 ฿7,957 - ฿11,403 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 ฿18,050. 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.
Return price
฿18,050
Distance
3679 km
Average flight time
3 hours 47 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 ฿4,840 and roundtrip prices from ฿18,050. 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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