NT$4,181 Cheap Flights from Washington (IAD) to Seattle (SEA)

View NT$4,181 flight on Tue, 2026/9/22Opens in a new window

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

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Cheap Flights from Washington to Seattle (IAD-SEA)

Prices were available within the past 7 days and start at NT$4,181 for one-way flights and NT$7,731 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$7,731 Roundtrip, found 20 hours ago
NT$7,731
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$7,731 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$10,730 Roundtrip, found 20 hours ago
NT$10,730
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$10,730 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$11,040 Roundtrip, found 20 hours ago
NT$11,040
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$11,040 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$11,361 Roundtrip, found 20 hours ago
NT$11,361
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$11,361 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$11,829 Roundtrip, found 20 hours ago
NT$11,829
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$11,829 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$11,986 Roundtrip, found 20 hours ago
NT$11,986
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$11,986 found 20 hours ago
American Airlines
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$12,150 Roundtrip, found 20 hours ago
NT$12,150
Roundtrip
found 20 hours ago
Select American Airlines flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$12,150 found 20 hours ago
Delta
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$13,097 Roundtrip, found 20 hours ago
NT$13,097
Roundtrip
found 20 hours ago
Select Delta flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$13,097 found 20 hours ago
American Airlines
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$13,124 Roundtrip, found 20 hours ago
NT$13,124
Roundtrip
found 20 hours ago
Select American Airlines flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$13,124 found 20 hours ago
United
Fri, Jun 5 - Thu, Jun 11
IAD
Washington
SEA
Seattle
NT$13,140 Roundtrip, found 20 hours ago
NT$13,140
Roundtrip
found 20 hours ago
Select United flight, departing Fri, Jun 5 from Washington to Seattle, returning Thu, Jun 11, priced at NT$13,140 found 20 hours ago

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 NT$7,731. 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 canceled online, but whether you incur a fee differs between airlines. If you do need to cancel your vacation, 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 kilometers. Set up a playlist of your favorite 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.
Roundtrip price
NT$7,731
Distance
3679 km
Average flight time
2 hours 48 mins

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