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Dulles International Airport to Seattle-Tacoma International Airport flight

Explore the cheapest one-way and round-trip flights from Dulles International Airport to Seattle-Tacoma International Airport over the next 90 days, with one-way fares from THB 4,830 and round-trip from THB 6,050. Based on Trip.com's latest 7-day flight data.

      • Cheapest nonstop
        IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Sun, Oct 18 | Alaska Airlines
        SEA 21:36
        5h 4m
        Direct
        IAD 05:40
        Seattle - Washington D.C. | Wed, Oct 21 | Alaska Airlines
        THB 6,280 THB 13,890
        55% off
        55% off
        THB 13,890 THB 6,280
      • IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Mon, Nov 2 | Alaska Airlines
        SEA 21:49
        4h 55m
        Direct
        IAD 05:44
        Seattle - Washington D.C. | Mon, Nov 9 | Alaska Airlines
        THB 6,300 THB 13,890
        55% off
        55% off
        THB 13,890 THB 6,300
      • IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Sun, Oct 18 | Delta Air Lines
        SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Wed, Oct 21 | Delta Air Lines
        THB 6,550 THB 13,890
        53% off
        53% off
        THB 13,890 THB 6,550
      • IAD 07:25
        5h 40m
        Direct
        SEA 10:05
        Washington D.C. - Seattle | Wed, Oct 7 | Delta Air Lines
        SEA 07:20
        5h 3m
        Direct
        DCA 15:23
        Seattle - Washington D.C. | Mon, Oct 12 | Delta Air Lines
        THB 7,920
        43% off
        THB 13,890 THB 7,920
      • IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Wed, Oct 7 | Alaska Airlines
        SEA 13:49
        5h 10m
        Direct
        DCA 21:59
        Seattle - Washington D.C. | Mon, Oct 12 | Alaska Airlines
        THB 8,640
        38% off
        THB 13,890 THB 8,640
      • IAD 07:00
        5h 37m
        Direct
        SEA 09:37
        Washington D.C. - Seattle | Sun, Sep 27 | Alaska Airlines
        SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Wed, Sep 30 | Alaska Airlines
        THB 9,290
        33% off
        THB 13,890 THB 9,290
      • IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Mon, Nov 2 | Delta Air Lines
        SEA 07:20
        5h 3m
        Direct
        DCA 15:23
        Seattle - Washington D.C. | Mon, Nov 9 | Delta Air Lines
        THB 9,300
        33% off
        THB 13,890 THB 9,300
      • IAD 06:05
        7h 55m
        1 stop
        SEA 11:00
        Washington D.C. - Seattle | Sat, Oct 17 | Delta Air Lines
        SEA 07:20
        5h 3m
        Direct
        DCA 15:23
        Seattle - Washington D.C. | Wed, Oct 21 | Delta Air Lines
        THB 6,050
        56% off
        THB 13,890 THB 6,050
      • IAD 07:00
        5h 37m
        Direct
        SEA 09:37
        Washington D.C. - Seattle | Fri, Oct 2 | Alaska Airlines
        SEA 16:27
        26h 32m
        1 stop
        DCA 21:59
        Seattle - Washington D.C. | Wed, Oct 7 | Frontier Airlines
        THB 9,620
        31% off
        THB 13,890 THB 9,620
      • IAD 17:57
        5h 47m
        Direct
        SEA 20:44
        Washington D.C. - Seattle | Thu, Oct 1 | Alaska Airlines
        SEA 16:27
        26h 32m
        1 stop
        DCA 21:59
        Seattle - Washington D.C. | Wed, Oct 7 | Frontier Airlines
        THB 9,620
        31% off
        THB 13,890 THB 9,620
      • IAD 06:00
        29h 58m
        1 stop
        SEA 08:58
        Washington D.C. - Seattle | Mon, Oct 19 | Frontier Airlines
        SEA 21:16
        30h 4m
        1 stop
        IAD 06:20
        Seattle - Washington D.C. | Wed, Oct 21 | Frontier Airlines
        THB 9,730
        30% off
        THB 13,890 THB 9,730
      • IAD 07:25
        5h 40m
        Direct
        SEA 10:05
        Washington D.C. - Seattle | Fri, Oct 2 | Delta Air Lines
        SEA 16:27
        26h 32m
        1 stop
        DCA 21:59
        Seattle - Washington D.C. | Wed, Oct 7 | Frontier Airlines
        THB 9,860
        28% off
        THB 13,890 THB 9,860
      • WAS 13:00
        17h 25m
        1 stop
        SEA 14:00
        Washington D.C. - Seattle | Sat, Sep 26 | Normal Airline
        SEA 15:00
        6h
        Direct
        WAS 16:00
        Seattle - Washington D.C. | Mon, Sep 28 | Normal Airline
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      • Cheapest nonstop
        IAD 07:25
        5h 40m
        Direct
        SEA 10:05
        Washington D.C. - Seattle | Fri, Sep 25 | Delta Air Lines
        THB 4,840 THB 9,150
        47% off
        47% off
        THB 9,150 THB 4,840
      • IAD 09:03
        5h 36m
        Direct
        SEA 11:39
        Washington D.C. - Seattle | Fri, Sep 25 | Alaska Airlines
        THB 4,960 THB 9,150
        46% off
        46% off
        THB 9,150 THB 4,960
      • IAD 07:57
        10h 20m
        1 stop
        SEA 15:17
        Washington D.C. - Seattle | Fri, Sep 25 | American Airlines
        THB 4,830 THB 9,150
        47% off
        47% off
        THB 9,150 THB 4,830
      • IAD 06:00
        30h 42m
        1 stop
        SEA 09:42
        Washington D.C. - Seattle | Mon, Oct 5 | Frontier Airlines
        THB 4,950
        46% off
        THB 9,150 THB 4,950
      • IAD 06:00
        30h 42m
        1 stop
        SEA 09:42
        Washington D.C. - Seattle | Thu, Oct 8 | Frontier Airlines
        THB 4,960
        46% off
        THB 9,150 THB 4,960
      • IAD 06:00
        30h 42m
        1 stop
        SEA 09:42
        Washington D.C. - Seattle | Fri, Oct 2 | Frontier Airlines
        THB 5,110
        44% off
        THB 9,150 THB 5,110
      • IAD 06:52
        9h 27m
        1 stop
        SEA 13:19
        Washington D.C. - Seattle | Tue, Oct 6 | American Airlines
        THB 5,290
        42% off
        THB 9,150 THB 5,290
      • IAD 06:00
        29h 58m
        1 stop
        SEA 08:58
        Washington D.C. - Seattle | Fri, Oct 9 | Frontier Airlines
        THB 5,500
        40% off
        THB 9,150 THB 5,500
      • IAD 06:00
        29h 58m
        1 stop
        SEA 08:58
        Washington D.C. - Seattle | Fri, Oct 23 | Frontier Airlines
        THB 5,780
        37% off
        THB 9,150 THB 5,780
      • IAD 06:00
        30h 42m
        1 stop
        SEA 09:42
        Washington D.C. - Seattle | Wed, Oct 7 | Frontier Airlines
        THB 5,880
        36% off
        THB 9,150 THB 5,880
      • IAD 06:00
        30h 42m
        1 stop
        SEA 09:42
        Washington D.C. - Seattle | Thu, Oct 1 | Frontier Airlines
        THB 6,450
        30% off
        THB 9,150 THB 6,450
      • IAD 14:46
        10h 34m
        1 stop
        SEA 22:20
        Washington D.C. - Seattle | Mon, Oct 19 | American Airlines
        THB 6,490
        28% off
        THB 9,150 THB 6,490
      • WAS 13:00
        17h 25m
        1 stop
        SEA 14:00
        Washington D.C. - Seattle | Sat, Sep 26 | Normal Airline
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Displayed flight fares from Dulles International Airport to Seattle-Tacoma International Airport are based on average prices across airlines for the next 3 months according to the latest Trip.com data.

Trip.com Price Insights: Flights from Dulles International Airport to Seattle-Tacoma International Airport

What is the cheapest month to fly from Dulles International Airport to Seattle-Tacoma International Airport?

The data is based on the past 12 months and shows the average one-way ticket prices from Dulles International Airport to Seattle-Tacoma International Airport for each month in the Trip.com database.

Based on Trip.com's data from the past 12 months, the cheapest one-way flights from Dulles International Airport to Seattle-Tacoma International Airport are usually in March, with an average price of THB 7,220. It is best to avoid December, when the average price can reach THB 16,370.

THB 16,370
THB 11,795
THB 7,220
THB 2,645
    Cheapest
  • THB 8,910
    Sep
  • THB 9,810
    Oct
  • THB 10,380
    Nov
  • THB 16,370
    Dec
  • THB 9,400
    Jan
  • THB 8,800
    Feb
  • THB 7,220
    Mar
  • THB 7,650
    Apr
  • THB 10,990
    May
  • THB 8,650
    Jun
  • THB 12,070
    Jul
  • THB 11,050
    Aug

What is the cheapest day of the week to fly from Dulles International Airport to Seattle-Tacoma International Airport?

The data is based on the past 12 months and shows the average ticket prices from Dulles International Airport to Seattle-Tacoma International Airport for each day of the week in the Trip.com database.

Based on Trip.com's data from the past 12 months, the cheapest departure day from Dulles International Airport to Seattle-Tacoma International Airport is Sunday, with average prices usually lower than other days. Avoid departing on Friday as prices are typically highest on that day.

THB 13,780
THB 11,340
THB 8,900
THB 6,460
    Cheapest
  • THB 9,940
    Mon
  • THB 9,020
    Tue
  • THB 10,080
    Wed
  • THB 11,390
    Thu
  • THB 13,780
    Fri
  • THB 10,860
    Sat
  • THB 8,900
    Sun

Which airline offers the cheapest flights from Dulles International Airport to Seattle-Tacoma International Airport?

The cheapest airline flying from Dulles International Airport to Seattle-Tacoma International Airport is American Airlines (from THB 4,830) among 8 carriers operating this route. Based on Trip.com's latest 7-day flight data.

American Airlines
From THB 4,830
Delta Air Lines
From THB 4,840
Frontier Airlines
From THB 4,950
Alaska Airlines
From THB 4,960
United Airlines
From THB 6,700
Air Canada
From THB 7,190
Sun Country Airlines
From THB 7,700
Southern Airways Express
From THB 15,580

Find more flights and airlines

What is the flight schedule from Dulles International Airport to Seattle-Tacoma International Airport?

Check the schedule for flights from Washington D.C. to Seattle and find the flight that best matches your travel plans.

Flight info.
Departure
Arrival
Weekly Schedule

  1. AA9392

    Dulles International Airport

    10:00

    IAD

    5h 48m

    12:48

    SEA

    S M T W T F S
    Search

  2. DL1015

    Dulles International Airport

    07:05

    IAD

    6h

    10:05

    SEA

    S M T W T F S
    Search

  3. AS1574

    Dulles International Airport

    07:00

    IAD

    5h 37m

    09:37

    SEA

    S M T W T F S
    Search

  4. AS375

    Dulles International Airport

    09:03

    IAD

    5h 36m

    11:39

    SEA

    S M T W T F S
    Search

  5. UA1128

    Dulles International Airport

    17:35

    IAD

    6h 7m

    20:10

    SEA

    S M T W T F S
    Search

  6. AS737

    Dulles International Airport

    17:46

    IAD

    5h 47m

    20:33

    SEA

    S M T W T F S
    Search

  7. AA3001

    Dulles International Airport

    06:32

    IAD

    1h 25m

    Direct

    07:57

    CLT

    S M T W T F S
    Search

  8. AA2407

    Charlotte Douglas International Airport

    08:36

    CLT

    5h 49m

    Direct

    11:25

    SEA

    S M T W T F S

  9. AA1863

    Dulles International Airport

    18:41

    IAD

    3h 22m

    Direct

    21:03

    DFW

    - - - W - - S
    Search

  10. AA1487

    Dallas Fort Worth International Airport

    20:50

    DFW

    4h 19m

    Direct

    23:09

    SEA

    - - - W - - S

  11. AA2617

    Dulles International Airport

    06:52

    IAD

    3h 18m

    Direct

    09:10

    DFW

    S M T W T F S
    Search

  12. AA717

    Dallas Fort Worth International Airport

    11:01

    DFW

    4h 18m

    Direct

    13:19

    SEA

    S M T W T F S

  13. F94409

    Dulles International Airport

    20:39

    IAD

    2h 11m

    Direct

    22:50

    ATL

    S M T W T F S
    Search

  14. F91449

    Hartsfield–Jackson Atlanta International Airport

    06:41

    ATL

    3h 23m

    Direct

    08:04

    DEN

    S M T W T F S

  15. F91175

    Denver International Airport

    13:07

    DEN

    3h 5m

    Direct

    15:12

    SEA

    S M T W T F S
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About Dulles International Airport and Seattle-Tacoma International Airport

Learn about Dulles International Airport (IAD) and Seattle-Tacoma International Airport (SEA) — including location, terminals, transportation, and travel tips.

Flight distance 3,705.38km
Cheapest one-way ticket price THB 4,830
Cheapest return ticket price THB 6,050

FAQs for Dulles International Airport to Seattle-Tacoma International Airport Flights

  • How long is the flight from Dulles International Airport to Seattle-Tacoma International Airport?

    Dulles International Airport to Seattle-Tacoma International Airport takes about 5 hours 13 minutes on average. Actual flight time may vary depending on route, weather and air traffic.
  • There are around 6 daily flights from Dulles International Airport (IAD) to Seattle-Tacoma International Airport (SEA).
  • The earliest flight from Dulles International Airport to Seattle-Tacoma International Airport departs at 07:00, and the last departs at 17:57, with about 9 flights per day. Flight times may change, so please check the latest departure and arrival times before you travel.
  • The route from Dulles International Airport (IAD) to Seattle-Tacoma International Airport (SEA) is quite popular. Without considering departure times or holidays, tickets cost around THB 18,020 in September, the most expensive month to book this route.
    • The distance from Seattle-Tacoma International Airport to downtown is about 17km, by taxi about 30 minutes.
  • American Airlines is a very popular airline operating an average of 1844 flights per month.
  • One-way flights from Dulles International Airport to Seattle-Tacoma International Airport currently start from THB 4,830, and round-trip fares start from THB 6,050. The current lowest fare is a American Airlines flight departing on Fri, Sep 25; prices may vary depending on availability.
  • Yes. Alaska Airlines, United Airlines and Delta Air Lines operate direct flights from Dulles International Airport to Seattle-Tacoma International Airport, with an average flight time of 5 hours 19 minutes, and around 41 weekly flights. Actual flight frequency may vary by season.
  • Based on Trip.com flight data for departures within the next 30 days with at most one stop, the average one-way price from Dulles International Airport to Seattle-Tacoma International Airport is THB 10,200. Prices may vary depending on the departure date, airline, and availability.
  • Dulles International Airport to Seattle-Tacoma International Airport operates around 42 weekly flights, mainly by Alaska Airlines, United Airlines and Delta Air Lines. Actual frequency may vary during holidays and seasonal schedule adjustments.
  • Enter Dulles International Airport and Seattle-Tacoma International Airport, select your departure date and number of passengers, then compare flights by price, flight duration, and baggage allowance. Once you've chosen a fare, review the change and refund rules, fill in passenger details, and pay to receive your booking confirmation.

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Note: Prices shown on this page are the estimated lowest prices and include all taxes and fees found in the last 24 hours.

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Prices displayed on this page are all-inclusive (including taxes, fuel surcharges, civil aviation development fund, etc.), with all fees confirmed before payment. Fees for luggage, meals, Wi-Fi, or other additional services are also included as shown in the flight cards.

Real-time pricing updates

Prices, availability, and travel information on this page have been updated within the last 24 hours—sometimes even in real time. The more popular the route, the more accurate the data.

Change & Cancellation Policy

Trip.com shows the cancellation and change policies for each flight ticket during the booking process, including any fees and applicable conditions. Please check the following scenarios:
Voluntary cancellation/change:
To request a change or cancellation, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and flight segment, and submit your request. Please note that additional charges may apply according to the airline's ticket policy.
Cancellation/change due to a flight schedule change:
If the flight schedule has changed and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please visit the customer support pages.