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

View AU$244 flight on Sun, 7 June 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 for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$513 Return, found 6 days ago
AU$513
Return
found 6 days ago
Select Delta flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$513 found 6 days ago
Alaska Airlines
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$557 Return, found 6 days ago
AU$557
Return
found 6 days ago
Select Alaska Airlines flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$557 found 6 days ago
Delta
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$565 Return, found 6 days ago
AU$565
Return
found 6 days ago
Select Delta flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$565 found 6 days ago
Alaska Airlines
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$603 Return, found 6 days ago
AU$603
Return
found 6 days ago
Select Alaska Airlines flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$603 found 6 days ago
Alaska Airlines
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$623 Return, found 6 days ago
AU$623
Return
found 6 days ago
Select Alaska Airlines flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$623 found 6 days ago
Delta
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$630 Return, found 6 days ago
AU$630
Return
found 6 days ago
Select Delta flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$630 found 6 days ago
Delta
Fri, 24 Apr - Fri, 1 May
IAD
Washington
SEA
Seattle
AU$645 Return, found 6 days ago
AU$645
Return
found 6 days ago
Select Delta flight, departing Fri, 24 Apr from Washington to Seattle, returning Fri, 1 May, priced at AU$645 found 6 days ago
United
Wed, 17 June - Wed, 1 July
IAD
Washington
SEA
Seattle
AU$649 Return, found 5 days ago
AU$649
Return
found 5 days ago
Select United flight, departing Wed, 17 June from Washington to Seattle, returning Wed, 1 July, priced at AU$649 found 5 days ago
United
Wed, 17 June - Wed, 1 July
IAD
Washington
SEA
Seattle
AU$663 Return, found 5 days ago
AU$663
Return
found 5 days ago
Select United flight, departing Wed, 17 June from Washington to Seattle, returning Wed, 1 July, priced at AU$663 found 5 days ago
American Airlines
Mon, 6 July - Sun, 12 July
IAD
Washington
SEA
Seattle
AU$1,047 Return, found 21 hours ago
AU$1,047
Return
found 21 hours ago
Select American Airlines flight, departing Mon, 6 July from Washington to Seattle, returning Sun, 12 July, priced at AU$1,047 found 21 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 AU$513. 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
Alaska Airlines, American Airlines, Delta, United
Return price
AU$513
Distance
3679 km
Average flight time
2 hours 56 mins

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