Cheap Flights from Washington (IAD) to Seattle (SEA) from HK$1,175~

View HK$1,175 flight on Wed, 27 Aug 2025Opens in a new window

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

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

Prices were available within the past 7 days and start at HK$1,175 for one-way flights and HK$2,263 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,263 Return, found 5 days ago
HK$2,263
Return
found 5 days ago
Select Delta flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,263 found 5 days ago
Delta
Mon, 15 Dec - Thu, 15 Jan
IAD
Washington
SEA
Seattle
HK$2,650 Return, found 6 days ago
HK$2,650
Return
found 6 days ago
Select Delta flight, departing Mon, 15 Dec from Washington to Seattle, returning Thu, 15 Jan, priced at HK$2,650 found 6 days ago
United
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,812 Return, found 5 days ago
HK$2,812
Return
found 5 days ago
Select United flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,812 found 5 days ago
Delta
Sun, 24 Aug - Sun, 31 Aug
IAD
Washington
SEA
Seattle
HK$2,822 Return, found 5 days ago
HK$2,822
Return
found 5 days ago
Select Delta flight, departing Sun, 24 Aug from Washington to Seattle, returning Sun, 31 Aug, priced at HK$2,822 found 5 days ago
Delta
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,823 Return, found 5 days ago
HK$2,823
Return
found 5 days ago
Select Delta flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,823 found 5 days ago
United
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,889 Return, found 5 days ago
HK$2,889
Return
found 5 days ago
Select United flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,889 found 5 days ago
Delta
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,900 Return, found 5 days ago
HK$2,900
Return
found 5 days ago
Select Delta flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,900 found 5 days ago
Delta
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$2,973 Return, found 5 days ago
HK$2,973
Return
found 5 days ago
Select Delta flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$2,973 found 5 days ago
United
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$3,048 Return, found 5 days ago
HK$3,048
Return
found 5 days ago
Select United flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$3,048 found 5 days ago
American Airlines
Mon, 18 Aug - Tue, 26 Aug
IAD
Washington
SEA
Seattle
HK$3,360 Return, found 5 days ago
HK$3,360
Return
found 5 days ago
Select American Airlines flight, departing Mon, 18 Aug from Washington to Seattle, returning Tue, 26 Aug, priced at HK$3,360 found 5 days ago

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

September is typically the cheapest month to fly

From HK$1,477 - HK$2,328 per traveller.

Graph displaying average flight prices per month

Washington to Seattle route information
Origin airport
Washington Dulles Intl.
Destination airport
Seattle - Tacoma Intl.
Return price
HK$2,263
Distance
3679 km
Average flight time
2 hours 48 mins

Flights from Chantilly to Seattle

Book cheap flights from Chantilly (IAD) to Seattle (SEA) on Expedia.com.hk. Find the best flight deals to destinations around the world for your next leisure or business travel on Expedia.com.hk.

Search for flights from Chantilly (IAD) to Seattle (SEA) to find great flight deals suitable to your travel date and time. Expedia.com.hk flight booking search engine is simple to use and looking for cheap flights is as easy as a click of a mouse or on your mobile devices.

Be assured that you’re seeing the best price guaranteed! Our friendly customer service representatives are here to serve you 24 hours day to provide assistance and answer any questions that you may have about booking your Chantilly (IAD) to Seattle (SEA) trip. Call us at 3077-4857 (direct number - 24 hours day for English).

Save more when combine your Seattle flight with a hotel for a package deal! Discover additional savings by booking in advance. Now you can find activities in Seattle and things to do in Seattle for your perfect vacation with Expedia Thing to Do.

If you would like to book flights to Seattle more flexibly, many prefer to purchase one-way tickets with options to take different airlines. A one way ticket to Seattle is HK$1,175 now!

 

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 HK$2,263. 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.

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