HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Seattle

$149+ Cheap flights from Dulles Intl (IAD) to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 6/13. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — SEA
Jun 3 — Jun 101
Wed 6/3
Wed 6/10
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Dulles Intl to Seattle with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.
Cheapflights Tip: The best prices from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl are usually found in January or February, booked 36 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from Dulles Intl to Seattle

Cheapest flights from Dulles Intl to Seattle
Explore the most affordable flight options available from Dulles Intl to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 4, 2026.

This Trip.com deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/59:12 am
IAD
-
SEA
1 stop28h 24m
Multiple Airlines
Thu 6/119:13 am
SEA
-
IAD
Nonstop4h 58m
Multiple Airlines
Deal found 4/29$277
This Expedia deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/309:50 am
IAD
-
SEA
1 stop27h 49m
Frontier
Mon 8/38:12 pm
SEA
-
IAD
1 stop9h 08m
Frontier
Deal found 4/30$278
This United Airlines deal was found by Cheapflights users on 5/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/55:18 pm
IAD
-
SEA
Nonstop5h 45m
United Airlines
Fri 9/117:35 pm
SEA
-
IAD
1 stop8h 30m
United Airlines
Deal found 5/3$279
This United Airlines deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/115:18 pm
IAD
-
SEA
Nonstop5h 45m
United Airlines
Mon 9/146:00 pm
SEA
-
IAD
1 stop8h 25m
United Airlines
Deal found 4/29$280
This Expedia deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/86:00 am
IAD
-
SEA
Nonstop5h 46m
Multiple Airlines
Sat 6/138:12 pm
SEA
-
IAD
1 stop9h 13m
Multiple Airlines
Deal found 4/30$282
This Travelocity deal was found by Cheapflights users on 5/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/289:50 am
IAD
-
SEA
1 stop27h 49m
Multiple Airlines
Tue 8/46:21 am
SEA
-
IAD
1 stop9h 24m
Multiple Airlines
Deal found 5/3$283
This Vliegwinkel deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Vliegwinkel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/49:12 am
IAD
-
SEA
1 stop28h 24m
Multiple Airlines
Wed 6/104:01 pm
SEA
-
IAD
Nonstop4h 58m
Multiple Airlines
Deal found 5/1$284
This Alaska Airlines deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/177:00 am
IAD
-
SEA
Nonstop5h 40m
Alaska Airlines
Sat 9/268:30 am
SEA
-
IAD
Nonstop5h 16m
Alaska Airlines
Deal found 4/30$285
This United Airlines deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/155:18 pm
IAD
-
SEA
Nonstop5h 45m
United Airlines
Wed 8/1911:56 pm
SEA
-
IAD
1 stop8h 32m
United Airlines
Deal found 5/1$287
This United Airlines deal was found by Cheapflights users on 5/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/49:00 am
IAD
-
SEA
Nonstop5h 51m
United Airlines
Thu 6/1111:20 pm
SEA
-
IAD
Nonstop5h 02m
United Airlines
Deal found 5/2$288
This Expedia deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/79:50 am
IAD
-
SEA
1 stop27h 49m
Multiple Airlines
Tue 7/219:04 pm
SEA
-
IAD
1 stop18h 41m
Multiple Airlines
Deal found 5/1$289
This Alaska Airlines deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/97:00 am
IAD
-
SEA
Nonstop5h 40m
Alaska Airlines
Sat 9/193:53 pm
SEA
-
IAD
Nonstop5h 06m
Alaska Airlines
Deal found 4/29$290

Find flight deals from Dulles Intl to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated May 4, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$277
(Trip.com)

One-way from

$149
(Super.com)

Popular in

June

Cheapest in

January

Average price

$424

Good round-trip deal

$419 or less

Good one-way deal

$243 or less
Provider with most accurate pricing for Washington, D.C. Dulles Intl-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Seattle/Tacoma Intl flights.
Search Deals
From Washington, D.C. Dulles Intl to Seattle/Tacoma Intl
Search Deals
One-way flight from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 14% potential increase in price ($64 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals
Price to beat on a round-trip flight from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl.
Search Deals
Price to beat on a one-way flight from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Dulles Intl to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated May 4, 2026.
Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 6/2

6:00 am-8:46 am

Nonstop5h 46m

Seattle/Tacoma Intl

Mon 6/8

3:53 pm-11:59 pm

Nonstop5h 06m

$311

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Wed 5/27

7:37 pm-1:25 pm

1 stop20h 48m

Seattle/Tacoma Intl

Thu 5/28

3:53 pm-11:59 pm

Nonstop5h 06m

$347

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Mon 7/6

9:00 am-11:51 am

Nonstop5h 51m

Seattle/Tacoma Intl

Tue 7/14

11:20 pm-7:22 am

Nonstop5h 02m

$359
Quickest round-trip

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 6/23

6:03 am-8:48 am

Nonstop5h 45m

Seattle/Tacoma Intl

Tue 7/7

10:43 pm-6:39 am

Nonstop4h 56m

$379

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Wed 6/24

7:49 pm-9:19 am

1 stop16h 30m

Seattle/Tacoma Intl

Fri 7/3

4:01 pm-11:59 pm

Nonstop4h 58m

$409

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Thu 6/4

6:33 am-11:57 am

1 stop8h 24m

Seattle/Tacoma Intl

Thu 6/11

11:20 pm-7:22 am

Nonstop5h 02m

$410

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Mon 6/8

6:00 am-8:46 am

Nonstop5h 46m

Seattle/Tacoma Intl

Sun 6/14

10:43 pm-6:39 am

Nonstop4h 56m

$411

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Tue 7/28

6:03 am-8:48 am

Nonstop5h 45m

Seattle/Tacoma Intl

Sat 8/1

9:13 am-5:11 pm

Nonstop4h 58m

$426

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Fri 5/29

6:33 am-11:57 am

1 stop8h 24m

Seattle/Tacoma Intl

Sat 5/30

7:00 am-7:02 pm

1 stop9h 02m

$467

Washington, D.C.Seattle

IAD - SEA

IADSEA

Washington, D.C. Dulles Intl

Mon 6/15

6:55 pm-11:59 pm

1 stop8h 04m

Seattle/Tacoma Intl

Mon 6/29

4:20 pm-12:25 am

Nonstop5h 05m

$476

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/3

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Compare providers for flights from Dulles Intl to Seattle

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Seattle in May.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
CheapTicketsDealPrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Dulles Intl Airport-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Seattle flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Dulles Intl to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Dulles Intl with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington, D.C. Dulles Intl Airport to Seattle

How far ahead should I book a flight from Washington, D.C. Dulles Intl Airport to Seattle?

The price you pay for your flight from Washington, D.C. Dulles Intl Airport to Seattle may vary depending on when you book. For the best chance of a lower fare, look to book 35 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Seattle?

Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Seattle (average of $231). Flying from Washington, D.C. Dulles Intl Airport to Seattle in June is currently the most expensive (average of $477). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IAD to SEA?

Find hourly flight availability from Dulles Intl to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated May 4, 2026.

One of the essential ways to save on airfare from Washington, D.C. Dulles Intl Airport to Seattle is to remain as flexible as possible. Flights that are in the evening tend to be the most expensive. A flight at noon could potentially save you up to 11% on airfare.

What is the cheapest day to fly from Washington, D.C. Dulles Intl Airport to Seattle?

Use this chart to determine the cheapest time to fly round-trip from Dulles Intl to Seattle. Price data was last updated on May 2, 2026.

Travelers seeking maximum savings on their Washington, D.C. Dulles Intl Airport to Seattle flight should consider departing on Tuesday at noon when fares are most often at their lowest. Monday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

How much does it cost to fly round-trip from Washington, D.C. Dulles Intl Airport to Seattle?

The best insider tips for Washington, D.C. Dulles Intl Airport to Seattle flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Washington, D.C. Dulles Intl Airport to Seattle trip
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on IAD

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated May 4, 2026.
See what other customers who have flown with Alaska Airlines,Delta, andHawaiian Airlines from Washington, D.C. Dulles Intl Airport to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Alaska Airlines
7.9
Good
12,325 reviews
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Delta
7.9
Good
8,459 reviews
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Hawaiian Airlines
7.8
Good
2,837 reviews
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
United Airlines
7.4
Good
9,681 reviews
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
American Airlines
7.1
Good
11,670 reviews
Alaska Airlines
7.9
Good
12,325 reviews

Boarding

8.1

Entertainment

7.0

Overall

7.9

Comfort

7.8

Food

7.1

Crew

8.5

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from Washington, D.C. Dulles Intl?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from Washington, D.C. Dulles Intl to Seattle. 6 airlines have flights to Seattle/Tacoma Intl from Washington, D.C. Dulles Intl on a regular basis. Booking flights from Washington, D.C. Dulles Intl to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 17 inbound flights from Washington, D.C. Dulles Intl per day.

  • How long is the flight from Washington, D.C. Dulles Intl Airport to Seattle?

    There are many flights that can get you from Washington, D.C. Dulles Intl Airport to Seattle in 5h 46m. Fly via Alaska Airlines or United Airlines to get the fastest option. Airlines will cover a distance of 2299 mi. Generally, flights for this route are nonstop.

  • What are the cheapest airlines flying from Washington, D.C. Dulles Intl Airport to Seattle round-trip?

    Cheapflights users have booked flights from Washington, D.C. Dulles Intl Airport to Seattle round-trip from $111. Other airlines that can offer you cheap pricing are Delta, from $136, and Hawaiian Airlines, from $138. Frontier is currently priced 70% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from Washington, D.C. Dulles Intl Airport to Seattle one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $116. Alaska Airlines flights start at $119 while deals on Delta start at $119 one-way.

  • What are the most reliable airlines from Washington, D.C. Dulles Intl Airport to Seattle?

    The top 3 most reliable airlines when flying from Washington, D.C. Dulles Intl Airport to Seattle are Lufthansa (87%), United Airlines (85%) and Japan Airlines (80%).

  • What are the cheapest flights from Washington, D.C. Dulles Intl Airport to Seattle?

    The cheapest flight price from Washington, D.C. Dulles Intl Airport to Seattle is $177. On average you can expect to pay $1,124. The most popular route, (Washington, D.C. Dulles Intl - Seattle/Tacoma Intl), can usually be booked for $236.

  • Can I find deals for flights from Dulles Intl to Seattle that include hotel bookings?

    Yes. In addition to deals on Dulles Intl to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Dulles Intl to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Seattle.

  • Can I find deals for business class flights from Dulles Intl to Seattle?

    Yes. Cheapflights offers flight deals from Dulles Intl to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Seattle (average of $231). Flying from Washington, D.C. Dulles Intl Airport to Seattle in June is currently the most expensive (average of $477). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tacoma
Ocean Shores
Olympia
Lynnwood
Lacey
Edmonds
Leavenworth
Snoqualmie
Tumwater
Tukwila
Puyallup
Kent
Renton
Kirkland
Ellensburg
Fife
Lakewood
Issaquah
Shoreline

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 6 airlines flying from Dulles Intl to Seattle

Discover the top 6 airlines that operate flights from Dulles Intl to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated May 4, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$111Average$252FlexibilityNo cancel feeOn-time62%
DeltaCheapest$136Average$353FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$138Average$361FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$199Average$428FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$230Average$430FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$336Average$527FlexibilityNo cancel feeOn-time71%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.