Cheap Flights From Seattle - Tacoma Intl. (SEA) To Washington Dulles Intl. (IAD)

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

The cheapest flights to Washington Dulles Intl. found within the past 7 days were CA $338 round trip and CA $172 one way. Prices and availability subject to change. Additional terms may apply.

Tue, Sep 15 - Wed, Sep 23
SEA
Seattle
IAD
Washington
CA $338 Roundtrip, found 1 day ago
CA $338
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Tue, Sep 15 from Seattle to Washington, returning Wed, Sep 23, priced at CA $338 found 1 day ago
Mon, Jun 8 - Mon, Jun 29
SEA
Seattle
IAD
Washington
CA $341 Roundtrip, found 4 days ago
CA $341
Roundtrip
found 4 days ago
Select Delta flight, departing Mon, Jun 8 from Seattle to Washington, returning Mon, Jun 29, priced at CA $341 found 4 days ago
Thu, Jun 4 - Sun, Jun 7
SEA
Seattle
IAD
Washington
CA $348 Roundtrip, found 4 days ago
CA $348
Roundtrip
found 4 days ago
Select Delta flight, departing Thu, Jun 4 from Seattle to Washington, returning Sun, Jun 7, priced at CA $348 found 4 days ago
Wed, Sep 16 - Sun, Sep 20
SEA
Seattle
IAD
Washington
CA $374 Roundtrip, found 1 day ago
CA $374
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Wed, Sep 16 from Seattle to Washington, returning Sun, Sep 20, priced at CA $374 found 1 day ago
Fri, Aug 28 - Sat, Sep 5
SEA
Seattle
IAD
Washington
CA $377 Roundtrip, found 5 days ago
CA $377
Roundtrip
found 5 days ago
Select Alaska Airlines flight, departing Fri, Aug 28 from Seattle to Washington, returning Sat, Sep 5, priced at CA $377 found 5 days ago
Wed, Sep 16 - Sun, Sep 20
SEA
Seattle
IAD
Washington
CA $401 Roundtrip, found 1 day ago
CA $401
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Wed, Sep 16 from Seattle to Washington, returning Sun, Sep 20, priced at CA $401 found 1 day ago
Thu, Sep 17 - Sun, Sep 20
SEA
Seattle
IAD
Washington
CA $408 Roundtrip, found 1 day ago
CA $408
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Thu, Sep 17 from Seattle to Washington, returning Sun, Sep 20, priced at CA $408 found 1 day ago
Thu, Jun 4 - Wed, Jun 10
SEA
Seattle
IAD
Washington
CA $411 Roundtrip, found 4 days ago
CA $411
Roundtrip
found 4 days ago
Select Alaska Airlines flight, departing Thu, Jun 4 from Seattle to Washington, returning Wed, Jun 10, priced at CA $411 found 4 days ago
Mon, Jun 1 - Sun, Jun 7
SEA
Seattle
IAD
Washington
CA $412 Roundtrip, found 4 days ago
CA $412
Roundtrip
found 4 days ago
Select Delta flight, departing Mon, Jun 1 from Seattle to Washington, returning Sun, Jun 7, priced at CA $412 found 4 days ago
Wed, Sep 16 - Sun, Sep 20
SEA
Seattle
IAD
Washington
CA $436 Roundtrip, found 1 day ago
CA $436
Roundtrip
found 1 day ago
Select Alaska Airlines flight, departing Wed, Sep 16 from Seattle to Washington, returning Sun, Sep 20, priced at CA $436 found 1 day ago

Frequently asked questions

Are there direct flights from Sea-Tac Airport to Washington Dulles Intl. Airport (IAD)?
Sometimes, it's the journey that counts; other times, it's all about the destination. If you're eager to get to where you're going fast, multiple airlines advertise direct flights from Sea-Tac Airport to Washington Dulles Intl. Airport (IAD), including Alaska Airlines and United Airlines.
What airlines fly from SEA to IAD?
If you're heading to Sterling from Seattle, there are several airlines with direct flights. One of the top carriers is Alaska Airlines (AS), which operates 52 flights each month. You should also check out the deals available through United Airlines (UA). This carrier operates 30 flights monthly on the Seattle to Sterling route. Be sure to compare the two airlines to score the best fare.
What is the best day to buy a plane ticket?
Airfares offered on Friday tend to be the cheapest, according to flight demand on Travelocity.ca in 2021. Purchasing your airfares on a Thursday or Saturday can also provide better value, however our advice if you're looking to save money is to avoid booking on a Wednesday or Sunday. Our data shows that those two days have the highest ticket values on average, so keep this in mind if you're browsing flight deals.
What are the cheapest days to fly?
Frequent travellers may already know this, but earlier in the week is often the cheapest time to fly. Flights departing on a Monday are the cheapest of the week. Since flights towards the middle of the week tend to be more popular, this causes the prices to rise. This is why, on average, airfares booked on Travelocity.ca in 2021 were most expensive for Wednesday departures.
How far in advance can you book a flight?
Here's the deal: It is typically possible to start comparing international airfares on Travelocity.ca up to 12 months in advance. However, it does depend on the carrier as not all airlines release their prices that far out. According to our 2021 flight demand trends, last minute planners can still bag a bargain with some of the cheapest fares appearing 2-4 weeks prior to their travel dates.*According to flight demand on Travelocity.ca from January to December 2021. Savings are subject to change and may vary depending on selections made.
*Price based on the lowest price found within past 24 hours and based upon one night stay for two adults over the next thirty days. Prices and availability subject to change. Additional terms may apply.