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

View AU$201 flight on Sat, 24 Oct 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.

American Airlines
Sat, 3 Oct - Wed, 7 Oct
IAD
Washington
SEA
Seattle
AU$399 Return, found 3 days ago
AU$399
Return
found 3 days ago
Select American Airlines flight, departing Sat, 3 Oct from Washington to Seattle, returning Wed, 7 Oct, priced at AU$399 found 3 days ago
Alaska Airlines
Fri, 21 Aug - Fri, 28 Aug
IAD
Washington
SEA
Seattle
AU$426 Return, found 11 hours ago
AU$426
Return
found 11 hours ago
Select Alaska Airlines flight, departing Fri, 21 Aug from Washington to Seattle, returning Fri, 28 Aug, priced at AU$426 found 11 hours ago
Alaska Airlines
Wed, 12 Aug - Wed, 26 Aug
IAD
Washington
SEA
Seattle
AU$428 Return, found 3 days ago
AU$428
Return
found 3 days ago
Select Alaska Airlines flight, departing Wed, 12 Aug from Washington to Seattle, returning Wed, 26 Aug, priced at AU$428 found 3 days ago
Delta
Wed, 30 Sept - Tue, 6 Oct
IAD
Washington
SEA
Seattle
AU$444 Return, found 3 days ago
AU$444
Return
found 3 days ago
Select Delta flight, departing Wed, 30 Sept from Washington to Seattle, returning Tue, 6 Oct, priced at AU$444 found 3 days ago
American Airlines
Sat, 3 Oct - Wed, 7 Oct
IAD
Washington
SEA
Seattle
AU$473 Return, found 3 days ago
AU$473
Return
found 3 days ago
Select American Airlines flight, departing Sat, 3 Oct from Washington to Seattle, returning Wed, 7 Oct, priced at AU$473 found 3 days ago
Alaska Airlines
Fri, 21 Aug - Fri, 28 Aug
IAD
Washington
SEA
Seattle
AU$484 Return, found 11 hours ago
AU$484
Return
found 11 hours ago
Select Alaska Airlines flight, departing Fri, 21 Aug from Washington to Seattle, returning Fri, 28 Aug, priced at AU$484 found 11 hours ago
American Airlines
Thu, 3 Sept - Mon, 7 Sept
IAD
Washington
SEA
Seattle
AU$486 Return, found 4 days ago
AU$486
Return
found 4 days ago
Select American Airlines flight, departing Thu, 3 Sept from Washington to Seattle, returning Mon, 7 Sept, priced at AU$486 found 4 days ago
Alaska Airlines
Wed, 12 Aug - Wed, 26 Aug
IAD
Washington
SEA
Seattle
AU$486 Return, found 3 days ago
AU$486
Return
found 3 days ago
Select Alaska Airlines flight, departing Wed, 12 Aug from Washington to Seattle, returning Wed, 26 Aug, priced at AU$486 found 3 days ago
Alaska Airlines
Fri, 21 Aug - Fri, 28 Aug
IAD
Washington
SEA
Seattle
AU$491 Return, found 11 hours ago
AU$491
Return
found 11 hours ago
Select Alaska Airlines flight, departing Fri, 21 Aug from Washington to Seattle, returning Fri, 28 Aug, priced at AU$491 found 11 hours ago
United
Fri, 21 Aug - Fri, 28 Aug
IAD
Washington
SEA
Seattle
AU$505 Return, found 11 hours ago
AU$505
Return
found 11 hours ago
Select United flight, departing Fri, 21 Aug from Washington to Seattle, returning Fri, 28 Aug, priced at AU$505 found 11 hours ago

Alternative airports near Seattle

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Seattle - Tacoma Intl. SEA. Cheapest option available. Average driving time to city centre is 20 minutes. Flights from AU$675
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city centre20 min
Flights from AU$675

Frequently asked questions

How much does a flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) cost?
You can find one-way and return flights from IAD to SEA with Expedia. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see our cheapest fares first, and use the Price Tracking tool to receive alerts when IAD to SEA ticket fares go up or down.
What is the cheapest month to fly from Washington, DC (IAD) to Seattle, WA (SEA)?
The cheapest months to fly from Washington, DC (IAD) to Seattle, WA (SEA) are typically during off-peak season when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you are able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
There are 4 airlines offering direct flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA). Here are some of the top carriers:
  • United operates 21 direct flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) every week.
  • Delta operates 7 direct flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) every week.
  • Starlux Airlines operates 7 direct flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) every week.
  • Japan Airlines operates 7 direct flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) every week.
What is the cheapest airline that flies from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Delta is one of the cheapest airlines offering nonstop return flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA), with tickets starting from around AU$402 for flights that can be booked for departure within the next year. Sun Country Airlines offers one of the cheapest connecting return flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) starting from around AU$425. These prices are per adult for economy/coach class. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.
How do I find cheap flights from Washington, DC (IAD) to Seattle, WA (SEA)?
To find a cheap flight from Washington, DC (IAD) to Seattle, WA (SEA), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The best airline to fly with from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) will differ from traveler to traveler. If you like to fly early, Delta offers early morning flights. If price is the most important factor, Delta typically offers the lowest fares. United offers the most daily flights from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.), which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The cheapest months to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) are typically January and February, with average return flights around AU$466. However, the most popular months for this route, meaning you'll find plenty of flight options, are June and July. If you're looking for the best balance, you might consider travelling in the shoulder seasons, like late spring or early autumn, when prices might be slightly higher than the cheapest months but you'll still have good availability and pleasant weather.
How many flights per day from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
You'll find around 4 nonstop flights per day from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA). For even more choices, look at flights that include layovers, as there are approximately 122 connecting flights per day. Some common connection points include Hartsfield-Jackson Atlanta Intl. (ATL), Charlotte-Douglas Intl. (CLT), and Denver Intl. (DEN).
What is the earliest flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The earliest flight from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) typically departs around 5:00 AM. This flight is operated by American Airlines. This is a seasonal service, active in February and March. An early departure like this can help you make the most of your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
You'll typically find the most flights from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) on a Friday, with around 59 flights available. This gives you plenty of options for your travel plans. Major airlines on this route include United, Delta, and Alaska Airlines. Fridays offer notably more flight options compared to other days of the week, making it a good day to find a flight that fits your schedule.
What are the most popular departure times for flights from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The most popular departure times for flights from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA) are in the morning, from 6am to 9am. Many major carriers, including Alaska Airlines, Delta and United, offer flights during this window. Many travellers prefer these early morning flights as they allow you to arrive at your destination with plenty of time to settle in or start your day.
How long does it take to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
A non-stop flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) typically takes around 5 hours 48 minutes. This route covers a distance of approximately 3,701 kilometres. If you opt for a one-stop flight, your travel time will be longer, usually around 9 hours 30 minutes. Flights with two or more stops will extend your journey even further, to about 13 hours 48 minutes. Keep in mind that actual flight times can vary due to factors like wind patterns and air traffic.
Can you fly business or first class from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
You can fly business class or first class between IAD and SEA. You can fly business class with Frontier Airlines and Delta.First class cabins are available on Alaska Airlines, United, Delta, and American Airlines.
How do I earn miles on a Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight with Expedia?
It's easy to earn miles on a Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Seattle, WA (SEA) from Washington, DC (IAD)?
If you're planning to travel to Seattle from Washington Dulles Intl. (IAD), you can fly directly into Seattle - Tacoma Intl. (SEA). Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), San Diego Intl. (SAN), or Denver Intl. (DEN) before reaching Seattle. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) at the last minute?
Typically, booking a last minute flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight and hotel package?
Securing a Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Washington, DC (IAD) to Seattle, WA (SEA)?
If you booked your Washington, DC (IAD) to Seattle, WA (SEA) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Washington Dulles Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, United
Return price
AU$398
Distance
3679 km
Average flight time
3 hours 46 mins

Book with confidence

Your quick guide to flights from Washington to Seattle

Pick up great flights from Washington to Seattle

With Expedia, you have your pick of flights a day with 20 airlines covering flights from Washington to Seattle. Whether you’re on a business trip, a family holiday or a luxury break, just enter your travel dates, hit search then check out your choice of flights. Select from return, one way or multi-city flights, and use the advance search tool if you want a direct or refundable flight. You can narrow your search to show you just your preferred cabin class and airline, too. It’s all easy. You can book direct flights from Washington to Seattle that take around hours.

Find cheap flights from Washington to Seattle

From the great flight deals with prices currently ranging from AU$399 to AU$505, you can choose to see the cheapest flights first. Generally, you can book the cheapest flights from Washington to Seattle around 4 to 6 weeks in advance. If your travel dates are flexible, try to avoid weekends and peak seasons – when you are more likely to grab the lowest prices. Even last minute, there are some impressive deals. The cheapest time to fly to Seattle is normally in October.

Reasons to book your flight from Washington to Seattle with Expedia

Expedia makes it easy to find, book, and travel, with everything you need all in one place. When you enter your travel details, find fantastic deals just for you on flight tickets from Washington to Seattle across all the main airline carriers, so you can save time, dollars, and hassle finding the perfect flight. If you think your plans could change, choose refundable flights so any changes won’t cost you more. Book your flight to Seattle right now and, if you join Expedia Rewards, you earn points this time and every time you travel with Expedia.

Your quick guide to flights from Washington to Seattle

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