S$157 Cheap Flights from Seattle to Washington

View S$157 flight on Wed, 16 Sept, 2026Opens in a new window

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

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Cheap Flights from Seattle to Washington (SEA-IAD)

Prices were available within the past 7 days and start at S$157 for one-way flights and S$396 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Thu, 9 Jul - Mon, 13 Jul
SEA
Seattle
IAD
Washington
S$396 Return, found 4 days ago
S$396
Return
found 4 days ago
Select Delta flight, departing Thu, 9 Jul from Seattle to Washington, returning Mon, 13 Jul, priced at S$396 found 4 days ago
Delta
Fri, 10 Jul - Sun, 12 Jul
SEA
Seattle
IAD
Washington
S$410 Return, found 4 days ago
S$410
Return
found 4 days ago
Select Delta flight, departing Fri, 10 Jul from Seattle to Washington, returning Sun, 12 Jul, priced at S$410 found 4 days ago
Delta
Thu, 9 Jul - Mon, 13 Jul
SEA
Seattle
IAD
Washington
S$441 Return, found 4 days ago
S$441
Return
found 4 days ago
Select Delta flight, departing Thu, 9 Jul from Seattle to Washington, returning Mon, 13 Jul, priced at S$441 found 4 days ago
United
Thu, 9 Jul - Mon, 13 Jul
SEA
Seattle
IAD
Washington
S$467 Return, found 4 days ago
S$467
Return
found 4 days ago
Select United flight, departing Thu, 9 Jul from Seattle to Washington, returning Mon, 13 Jul, priced at S$467 found 4 days ago
Delta
Thu, 28 May - Mon, 8 Jun
SEA
Seattle
IAD
Washington
S$469 Return, found 7 hours ago
S$469
Return
found 7 hours ago
Select Delta flight, departing Thu, 28 May from Seattle to Washington, returning Mon, 8 Jun, priced at S$469 found 7 hours ago
Delta
Mon, 1 Jun - Tue, 9 Jun
SEA
Seattle
IAD
Washington
S$474 Return, found 3 days ago
S$474
Return
found 3 days ago
Select Delta flight, departing Mon, 1 Jun from Seattle to Washington, returning Tue, 9 Jun, priced at S$474 found 3 days ago
United
Thu, 9 Jul - Mon, 13 Jul
SEA
Seattle
IAD
Washington
S$479 Return, found 4 days ago
S$479
Return
found 4 days ago
Select United flight, departing Thu, 9 Jul from Seattle to Washington, returning Mon, 13 Jul, priced at S$479 found 4 days ago
Delta
Fri, 10 Jul - Sun, 12 Jul
SEA
Seattle
IAD
Washington
S$485 Return, found 4 days ago
S$485
Return
found 4 days ago
Select Delta flight, departing Fri, 10 Jul from Seattle to Washington, returning Sun, 12 Jul, priced at S$485 found 4 days ago
American Airlines
Thu, 28 May - Mon, 8 Jun
SEA
Seattle
IAD
Washington
S$487 Return, found 7 hours ago
S$487
Return
found 7 hours ago
Select American Airlines flight, departing Thu, 28 May from Seattle to Washington, returning Mon, 8 Jun, priced at S$487 found 7 hours ago
United
Thu, 4 Jun - Wed, 10 Jun
SEA
Seattle
IAD
Washington
S$492 Return, found 4 days ago
S$492
Return
found 4 days ago
Select United flight, departing Thu, 4 Jun from Seattle to Washington, returning Wed, 10 Jun, priced at S$492 found 4 days ago

Frequently asked questions

How much is a flight from Sea-Tac Airport to Washington Dulles Intl. Airport (IAD)?
The lowest price advertised for a round-trip journey between SEA and Washington Dulles Intl. Airport (IAD) is S$396. But you better act quick. This price is based on fares quoted within the last 7 days on Expedia for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from Sea-Tac Airport to Washington Dulles Intl. Airport (IAD)?
Most flights can be cancelled online, but whether or not you incur a fee varies between airlines. If you do need to cancel your getaway, follow the instructions in the Customer Service Portal.
How do I find cheap flights from SEA to IAD 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 SEA to IAD flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Sea-Tac Airport to Dulles Intl. Airport?
The flight distance between Sea-Tac Airport (SEA) and Washington Dulles Intl. Airport (IAD) (IAD) is 3,700 kilometres. Sneak in a nap or make a start on the latest bestseller and the trip will zip on by.
Which airlines fly direct from Seattle - Tacoma Intl. Airport (SEA) to Dulles Intl. Airport?
There are a few airlines that fly directly from Seattle - Tacoma Intl. Airport (SEA) to IAD. United Airlines (UA) is a great choice, offering 60 flights every month. Offering 56 flights every month along this route, Alaska Airlines (AS) is another good option.
Are SEA to Washington Dulles Intl. Airport (IAD) flight tickets cheaper when they're purchased at the last minute?
Booking last minute from Seattle - Tacoma Intl. Airport (SEA) to IAD can be hit-or-miss. You might be lucky and score a bargain, but you could also miss out completely! If you'd rather play it safe and start your travel planning early on, Expedia compares flight deals up to a year in advance. Just remember that not all airlines advertise their prices that far in advance. Our top tip? Check back often as prices are updated regularly.

Travel information

Origin airport
Seattle - Tacoma Intl.
Destination airport
Washington Dulles Intl.
Return price
S$395
Distance
3679 km
Average flight time
8 hours 2 mins

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