Cheap flights from Seattle to Washington Dulles

Compare Seattle to Washington Dulles flight deals

Find the cheapest month or even day of the year to fly to Washington Dulles

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Flight deals from Seattle to Washington Dulles Airport

Looking for a cheap last-minute deal or the best return flight from Seattle to Washington Dulles Airport? If you want to travel next month, return fares start from $268. Find the lowest prices on one-way and return tickets right here.

Washington D.C..$140 per passenger.Departing Mon, 4 May.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Mon, 4 May, arriving in Washington Dulles.Price includes taxes and charges.From $140, select.

Washington D.C..$140 per passenger.Departing Mon, 20 Apr.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Seattle / Tacoma International on Mon, 20 Apr, arriving in Washington Dulles.Price includes taxes and charges.From $140, select.

Washington D.C..$153 per passenger.Departing Mon, 11 May.One-way flight with United.Outbound direct flight with United departs from Seattle / Tacoma International on Mon, 11 May, arriving in Washington Dulles.Price includes taxes and charges.From $153, select.

Washington D.C..$153 per passenger.Departing Sat, 18 Apr.One-way flight with United.Outbound direct flight with United departs from Seattle / Tacoma International on Sat, 18 Apr, arriving in Washington Dulles.Price includes taxes and charges.From $153, select.

Washington D.C..$153 per passenger.Departing Tue, 2 Jun.One-way flight with United.Outbound direct flight with United departs from Seattle / Tacoma International on Tue, 2 Jun, arriving in Washington Dulles.Price includes taxes and charges.From $153, select.

Washington D.C..$184 per passenger.Departing Wed, 25 Mar.One-way flight with Hawaiian Airlines.Outbound direct flight with Hawaiian Airlines departs from Seattle / Tacoma International on Wed, 25 Mar, arriving in Washington Dulles.Price includes taxes and charges.From $184, select.

Washington D.C..$269 per passenger.Departing Fri, 17 Jul.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Seattle / Tacoma International on Fri, 17 Jul, arriving in Washington Dulles.Price includes taxes and charges.From $269, select.

Washington D.C..$280 per passenger.Departing Tue, 7 Jul.One-way flight with United.Outbound direct flight with United departs from Seattle / Tacoma International on Tue, 7 Jul, arriving in Washington Dulles.Price includes taxes and charges.From $280, select.

Washington D.C..$280 per passenger.Departing Tue, 11 Aug.One-way flight with United.Outbound direct flight with United departs from Seattle / Tacoma International on Tue, 11 Aug, arriving in Washington Dulles.Price includes taxes and charges.From $280, select.

Washington D.C..$281 per passenger.Departing Tue, 8 Sep.One-way flight with Delta.Outbound direct flight with Delta departs from Seattle / Tacoma International on Tue, 8 Sep, arriving in Washington Dulles.Price includes taxes and charges.From $281, select.

Washington D.C..$281 per passenger.Departing Tue, 20 Oct.One-way flight with Delta.Outbound direct flight with Delta departs from Seattle / Tacoma International on Tue, 20 Oct, arriving in Washington Dulles.Price includes taxes and charges.From $281, select.

Find the cheapest month to fly from Seattle to Washington Dulles

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Seattle to Washington Dulles flights are currently cheapest in April.

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Direct flights from Seattle to Washington Dulles

Seattle to Washington Dulles: Alternative routes

Compare routes from Seattle to Washington D.C. below. You may find an airport to fly into that's cheaper, faster, or easier than Washington Dulles.

Seattle to Washington D.C.: Flight information

The things to know before you go.

Cheapest flight found	$140
Cheapest month to fly	May
Average flight time	5 hrs, 4 mins
Most popular airline	Qatar Airways
Average flights per week	153

Check out these Washington D.C. hotels

Ready to plan your stay? Other travellers rate these Washington D.C. hotels for cleanliness, service and location.

Sonder Georgetown C&O

2.27 km from city centre

$1,024

Per night

The Fairmont Washington DC

1.72 km from city centre

$766

Per night

The Ritz-Carlton, Washington, D.C.

1.47 km from city centre

$1,318

Per night

Sonder Georgetown C&O

2.27 km from city centre

$1,024

Per night

The Fairmont Washington DC

1.72 km from city centre

$766

Per night

The Ritz-Carlton, Washington, D.C.

1.47 km from city centre

$1,318

Per night

Explore top-rated hotels

Finding cheap flights from Seattle to Washington Dulles: Frequently asked questions

How much are return flights from Seattle to Washington Dulles?

The best price we found for a return flight from Seattle to Washington Dulles is $268. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.

How long does it take to fly from Seattle to Washington Dulles?

5 hours and 4 minutes is the average flight time from Seattle to Washington Dulles.

Which airlines fly direct from Seattle to Washington Dulles?

Qatar Airways, United and Alaska Airlines fly direct from Seattle to Washington Dulles.

How many flights are there a week from Seattle to Washington Dulles?

As of March 2026, there are 153 flights per week flying from Seattle to Washington Dulles.

When is the cheapest time to fly from Seattle to Washington Dulles?

The cheapest month to fly from Seattle to Washington Dulles is usually April.

Which upcoming date is cheapest to fly from Seattle to Washington Dulles Airport on?

After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Seattle to Washington Dulles Airport on Tuesday, 14 April 2026.

Can I get a direct flight from Seattle to Washington Dulles Airport?

Yes – the average flight time is 5 hours and 4 minutes.

How can I find the best flight deal to Washington Dulles?

We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Washington Dulles but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

When is the best time to book flights to Washington D.C.?

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Washington D.C. is around 40 days in advance, so don’t leave your flight to the last minute.

Which is the cheapest airline to fly from Seattle to Washington Dulles with?

The cheapest airline that flies to Washington Dulles is Delta .

Flying from Seattle to Washington Dulles International Airport (IAD): What you need to know

Your trip gets off the ground at Seattle's main airport, Seattle-Tacoma International Airport (SEA). Explore the options for catching a flight from Seattle to Washington Dulles International Airport (IAD) departing from this terminal.
Expect to be in the air for 5 hours. That's the average journey time for a direct Seattle to Washington Dulles International Airport flight.
Washington DC is three hours ahead of Seattle. Washington Dulles International Airport is located in Washington DC, which operates on the UTC-5 timezone.
The most popular route is from Seattle-Tacoma International Airport (SEA) to Washington Dulles International Airport (IAD), with 37 direct weekly services. If you're eager to be on your way, the earliest flight from SEA to IAD is the 8am United Airlines service. If you prefer to leave later in the day, the last departure is at 11:40pm with Alaska Airlines.
Your flight from Seattle to IAD won't wait if you're late, so don't forget to check in on time. Arrive up to one hour in advance for domestic flights and two hours ahead when you're flying internationally.
July is a busy month for air travel. If you're heading away then or around a major holiday like Thanksgiving, Memorial Day or Christmas, get there even earlier. Aim for at least two hours ahead for domestic flights and as much as four hours for international journeys.

Airports in Seattle

Seattle-Tacoma International Airport (SEA)

Seattle-Tacoma International Airport (SEA) offers an easy route to your destination. Nonstop flights from Seattle to Washington Dulles International Airport (IAD) leave from this terminal.
Choose from a variety of carriers that operate direct flights from Seattle to Washington Dulles International Airport leaving from SEA. Get on board with any of these:
Alaska Airlines sees the most traveller bookings for flights from SEA to IAD.
United is the most consistent performer for punctuality on this route.
SEA is about 23 kilometres from central Seattle. If you're catching a taxi, driving or ride-sharing from the centre, it'll take 25 minutes or so to get there, depending on traffic. If you're taking public transport, expect the travel time to be around 35 minutes.
Looking for a convenient hotel near Seattle-Tacoma International Airport? If you're catching an early flight from Seattle to Washington Dulles International Airport, these stays will have you sleeping a quick hop from check-in:
Seattle-Tacoma International Airport has a solid on-time performance, making delays less likely. Departures from SEA touch down on schedule 80% of the time.

Seattle Paine Field International Airport (PAE)

You can get to PAE from central Seattle in approximately 40 minutes by car (depending on traffic conditions). The ride on public transport takes roughly 1 hour 30 minutes to cover the 40 kilometres or so.
Get your holiday started early with an extra night away from home. Before catching your Seattle to IAD flight, stay in one of these hotels close to Seattle Paine Field International Airport:
Seattle Paine Field International Airport has a reputation for reliability and timeliness. 80% of flights taking off from here arrive right when they're supposed to.

About Washington Dulles International Airport (IAD)

Have a late flight from Seattle to Washington Dulles International Airport? Don't let it end in exhaustion. Check in to one of these hotels near IAD and give yourself a well-earned lights-out:
To lock in the lowest price, reserve your ride around one week ahead of your Seattle to Washington Dulles International Airport flight.
You'll find IAD at 1 Saarinen Circle.

Getting from Washington Dulles International Airport (IAD) to central Washington DC

From Washington Dulles International Airport, central Washington DC is around 40 kilometres away. It takes about 45 minutes to reach the city centre by car.
If you're travelling by public transport, expect a journey time of around 1 hour 10 minutes.

How to find the cheapest flights from Seattle to Washington Dulles International Airport (IAD)

The cheapest price we've found for a one-way ticket from Seattle to Washington Dulles International Airport is $140. For a return flight on this route, the best price is $268. Depending on when and how early you book, these fares may change.
Booking ahead of time is often the key to scoring a cheap flight from Seattle to IAD. Fares tend to rise as demand increases, so the closer your departure date, the more you'll likely pay.
The 'Whole month' search tool shows you the cheapest Seattle to Washington Dulles International Airport tickets throughout the month. It's a good way to find a bargain if your plans aren't set in stone.
You don't need to check back in every day to find out if fares have dropped when you create a Price Alert. We'll notify you the moment a new deal shows up on plane tickets from Seattle to IAD.
Filters make it easier to land a deal on your flight from Seattle to Washington Dulles International Airport. Choose the flight times, carriers and stops that look good to you. Then sort the results by 'Cheapest' to find the most affordable option fast.

The best time to fly from Seattle to Washington Dulles International Airport (IAD)

It's time to decide when to book your flight from Seattle to Washington Dulles International Airport (IAD). June is the busiest month to travel to Washington DC. If you like things a bit more low-key, go in February.
The warmest month in Washington DC is July, with temperatures ranging between 19ºC (66ºF) and 33ºC (91ºF). Lock in your Seattle to IAD plane ticket then if this is the type of weather you enjoy.
If you want cooler conditions, search for a cheap ticket from Seattle to Washington Dulles International Airport in January when temperatures are between -6ºC (21ºF) and 10ºC (50ºF).

More about Washington DC

Start your Washington DC trip right by choosing the perfect place to stay. Once you've booked your flight from Seattle to Washington Dulles International Airport, check out our selection of accommodation options including:
Your Washington DC visit should come with a side of sightseeing. Big-name attractions worth exploring include Lincoln Memorial, The White House and Smithsonian National Museum of Natural History.

Explore more of the United States

Philadelphia is just one of the many cities in the United States waiting to be explored once you've seen the sights of Washington DC. Around 225 kilometres away to the northeast, check out popular attractions including Independence Hall, Liberty Bell and Philadelphia Museum of Art.
Virginia Beach is another essential stop in the United States and is around 274 kilometres southeast of Washington DC. No journey is complete without dropping by Virginia Beach Boardwalk, Resort Beach and Neptune's Park.