£106 Cheap Flights from Washington (IAD) to Seattle (SEA)

View £106 flight on Tue, 15 Sept 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 and start at £106 for one-way flights and £182 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Fri, 5 Jun - Thu, 25 Jun
IAD
Washington
SEA
Seattle
£182 Return, found 6 days ago
£182
Return
found 6 days ago
Select Delta flight, departing Fri, 5 Jun from Washington to Seattle, returning Thu, 25 Jun, priced at £182 found 6 days ago
Alaska Airlines
Fri, 5 Jun - Thu, 11 Jun
IAD
Washington
SEA
Seattle
£214 Return, found 4 days ago
£214
Return
found 4 days ago
Select Alaska Airlines flight, departing Fri, 5 Jun from Washington to Seattle, returning Thu, 11 Jun, priced at £214 found 4 days ago
Delta
Tue, 14 Jul - Wed, 22 Jul
IAD
Washington
SEA
Seattle
£217 Return, found 4 days ago
£217
Return
found 4 days ago
Select Delta flight, departing Tue, 14 Jul from Washington to Seattle, returning Wed, 22 Jul, priced at £217 found 4 days ago
Alaska Airlines
Fri, 5 Jun - Mon, 8 Jun
IAD
Washington
SEA
Seattle
£229 Return, found 4 days ago
£229
Return
found 4 days ago
Select Alaska Airlines flight, departing Fri, 5 Jun from Washington to Seattle, returning Mon, 8 Jun, priced at £229 found 4 days ago
Alaska Airlines
Tue, 19 May - Sat, 6 Jun
IAD
Washington
SEA
Seattle
£231 Return, found 6 days ago
£231
Return
found 6 days ago
Select Alaska Airlines flight, departing Tue, 19 May from Washington to Seattle, returning Sat, 6 Jun, priced at £231 found 6 days ago
Alaska Airlines
Sun, 23 Aug - Wed, 26 Aug
IAD
Washington
SEA
Seattle
£240 Return, found 5 days ago
£240
Return
found 5 days ago
Select Alaska Airlines flight, departing Sun, 23 Aug from Washington to Seattle, returning Wed, 26 Aug, priced at £240 found 5 days ago
Alaska Airlines
Sun, 23 Aug - Wed, 26 Aug
IAD
Washington
SEA
Seattle
£241 Return, found 5 days ago
£241
Return
found 5 days ago
Select Alaska Airlines flight, departing Sun, 23 Aug from Washington to Seattle, returning Wed, 26 Aug, priced at £241 found 5 days ago
Alaska Airlines
Mon, 1 Jun - Mon, 8 Jun
IAD
Washington
SEA
Seattle
£245 Return, found 4 days ago
£245
Return
found 4 days ago
Select Alaska Airlines flight, departing Mon, 1 Jun from Washington to Seattle, returning Mon, 8 Jun, priced at £245 found 4 days ago
United
Tue, 16 Jun - Fri, 3 Jul
IAD
Washington
SEA
Seattle
£270 Return, found 6 days ago
£270
Return
found 6 days ago
Select United flight, departing Tue, 16 Jun from Washington to Seattle, returning Fri, 3 Jul, priced at £270 found 6 days ago
American Airlines
Sun, 15 Nov - Thu, 3 Dec
IAD
Washington
SEA
Seattle
£282 Return, found 6 days ago
£282
Return
found 6 days ago
Select American Airlines flight, departing Sun, 15 Nov from Washington to Seattle, returning Thu, 3 Dec, priced at £282 found 6 days 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 £282
SEA
Seattle - Tacoma Intl.
Cheapest
Average driving time to city centre20 min
Flights from £282

Frequently asked questions

How much does a flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) cost?
One-way flights typically cost between £189 and £996 and return flights often range between £189 and £996. 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 the cheapest fares first, and use the Price Tracking tool to receive alerts when Anaa (AAA) to Toronto, ON (YYZ-Pearson Intl.) ticket fares go up or down.
What is the cheapest month to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
January is typically the cheapest month to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.), with average return fares of approximately £434. This is about 27% lower than the average price throughout the year. January sees lower prices because it falls after the holiday travel rush, when demand drops and airlines compete for bookings. Other cheap months to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) include February and September.
Which airlines fly direct from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Enter IAD to SEA and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
How do I find cheap flights from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
To find a cheap flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.), 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) to Seattle, WA (SEA) will differ from traveller to traveller. If you like to fly early, AS offers early morning flights. If price is the most important factor, UA typically offers the lowest fares. UA offers the most daily flights from Washington, DC (IAD) to Seattle, WA (SEA), which is brilliant 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.)?
When you're planning your trip from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.), it's helpful to know the best times to fly. Based on booking data from the past year, you'll find the cheapest flights in January and February, with average prices around £434. These months are ideal if saving money is your top priority. If you're looking for the most popular times to travel, which often means more flight options and potentially better schedules, consider March or July. While these might not be the absolute cheapest, they are popular for a reason, offering a good balance for many travellers.
How many flights per day from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
There are approximately 4 nonstop flights per day from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA). For even more choice, look at flights that include layovers, as there are around 72 connecting flights per day. Some common connection points include Denver Intl. (DEN), Hartsfield-Jackson Atlanta Intl. (ATL), and Charlotte-Douglas Intl. (CLT).
What is the earliest flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The earliest flight from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) typically departs at approximately 5:00 AM local time, operated by American Airlines. This is a seasonal service active in February and March. An early departure like this can help you maximise 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.)?
If you're flying from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.), you'll typically find the most flights on a Thursday, with around 55 flights available. This gives you plenty of options to choose from. Major airlines on this route include United Airlines, Delta Air Lines, and Alaska Airlines. Flight schedules are fairly consistent throughout the week, with Thursday offering only slightly more flights than other days.
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 early morning, between 6am and 9am. This accounts for around 36% of total traffic. Many major carriers, including Delta Air Lines, Alaska Airlines and United Airlines, offer flights during this window. Many travellers prefer these times as they allow for an early start to their journey, getting them to their destination with plenty of time left in the day.
How long does it take to fly from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Direct flights from IAD to SEA usually take about 6 hours, traveling roughly 2,300 miles. If you opt for a connecting flight, expect to add around 4 hours to your journey. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Select the "Business class" and "First class" filters when looking for IAD to SEA flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
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 from Washington Dulles Intl. (IAD)?
From Washington Dulles Intl. (IAD), you can fly directly into Seattle - Tacoma Intl. (SEA) to reach Seattle. Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), San Diego Intl. (SAN), 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-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
If you booked your Washington, DC (IAD-Washington Dulles Intl.) to Seattle, WA (SEA-Seattle - Tacoma Intl.) 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
Return price
£182
Distance
3679 km
Average flight time
2 hours 48 mins

Book with confidence

Compare flights from Washington to Seattle easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Washington to Seattle. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Seattle - Tacoma Intl. in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Washington Dulles Intl. to Seattle - Tacoma Intl..  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Washington Dulles Intl. (IAD) to Seattle - Tacoma Intl. (SEA)

The easiest way to view the best deals on flights from Washington to Seattle today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Washington Dulles Intl. to Seattle - Tacoma Intl. start at just £182 and range up to £282.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near Washington and Seattle
  • booking your flight during June, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your Washington to Seattle flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Washington Dulles Intl. to Seattle - Tacoma Intl. for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Compare flights from Washington to Seattle easily and book with confidence

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