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Seattle-Tacoma International Airport to Dulles International Airport flight

Explore the cheapest one-way and round-trip flights from Seattle-Tacoma International Airport to Dulles International Airport over the next 90 days, with one-way fares from THB 4,610 and round-trip from THB 5,900. Based on Trip.com's latest 7-day flight data.

      • Cheapest nonstop
        SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Sat, Oct 17 | Alaska Airlines
        IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Fri, Oct 23 | Alaska Airlines
        THB 5,900 THB 11,430
        48% off
        48% off
        THB 11,430 THB 5,900
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Fri, Oct 16 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Mon, Oct 19 | Delta Air Lines
        THB 6,400 THB 11,430
        44% off
        44% off
        THB 11,430 THB 6,400
      • SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Wed, Oct 14 | Alaska Airlines
        IAD 09:38
        5h 42m
        Direct
        SEA 12:20
        Washington D.C. - Seattle | Tue, Oct 20 | Alaska Airlines
        THB 6,530 THB 11,430
        43% off
        43% off
        THB 11,430 THB 6,530
      • SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Fri, Oct 16 | Alaska Airlines
        IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Mon, Oct 19 | Alaska Airlines
        THB 7,490
        34% off
        THB 11,430 THB 7,490
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Fri, Oct 23 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Sat, Oct 31 | Delta Air Lines
        THB 7,820
        32% off
        THB 11,430 THB 7,820
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Thu, Oct 22 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Thu, Oct 29 | Delta Air Lines
        THB 7,830
        31% off
        THB 11,430 THB 7,830
      • SEA 16:30
        4h 50m
        Direct
        IAD 00:20
        Seattle - Washington D.C. | Wed, Nov 11 | Delta Air Lines
        IAD 07:00
        6h 5m
        Direct
        SEA 10:05
        Washington D.C. - Seattle | Tue, Nov 17 | Delta Air Lines
        THB 7,850
        31% off
        THB 11,430 THB 7,850
      • SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Wed, Oct 21 | Alaska Airlines
        IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Wed, Oct 28 | Alaska Airlines
        THB 7,860
        31% off
        THB 11,430 THB 7,860
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Tue, Oct 6 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Tue, Oct 13 | Delta Air Lines
        THB 7,860
        31% off
        THB 11,430 THB 7,860
      • SEA 16:30
        4h 50m
        Direct
        IAD 00:20
        Seattle - Washington D.C. | Mon, Nov 16 | Delta Air Lines
        IAD 07:00
        6h 5m
        Direct
        SEA 10:05
        Washington D.C. - Seattle | Mon, Nov 23 | Delta Air Lines
        THB 7,860
        31% off
        THB 11,430 THB 7,860
      • SEA 21:49
        4h 55m
        Direct
        IAD 05:44
        Seattle - Washington D.C. | Mon, Nov 9 | Alaska Airlines
        IAD 07:46
        5h 50m
        Direct
        SEA 10:36
        Washington D.C. - Seattle | Sat, Nov 14 | Alaska Airlines
        THB 8,000
        30% off
        THB 11,430 THB 8,000
      • SEA 19:00
        8h 20m
        1 stop
        IAD 06:20
        Seattle - Washington D.C. | Fri, Oct 16 | Frontier Airlines
        DCA 14:00
        22h 51m
        1 stop
        SEA 09:51
        Washington D.C. - Seattle | Thu, Oct 22 | Frontier Airlines
        THB 7,740
        32% off
        THB 11,430 THB 7,740
      • SEA 13:00
        17h 25m
        1 stop
        WAS 14:00
        Seattle - Washington D.C. | Mon, Oct 5 | Normal Airline
        WAS 15:00
        6h
        Direct
        SEA 16:00
        Washington D.C. - Seattle | Wed, Oct 7 | Normal Airline
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      • Cheapest nonstop
        SEA 21:36
        5h 4m
        Direct
        IAD 05:40
        Seattle - Washington D.C. | Mon, Oct 26 | Alaska Airlines
        THB 4,610 THB 7,750
        41% off
        41% off
        THB 7,750 THB 4,610
      • SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Thu, Oct 29 | Alaska Airlines
        THB 4,660 THB 7,750
        40% off
        40% off
        THB 7,750 THB 4,660
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Mon, Oct 26 | Delta Air Lines
        THB 4,670 THB 7,750
        40% off
        40% off
        THB 7,750 THB 4,670
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Thu, Oct 29 | Delta Air Lines
        THB 5,040
        35% off
        THB 7,750 THB 5,040
      • SEA 21:49
        4h 55m
        Direct
        IAD 05:44
        Seattle - Washington D.C. | Mon, Nov 16 | Alaska Airlines
        THB 5,280
        32% off
        THB 7,750 THB 5,280
      • SEA 16:30
        4h 50m
        Direct
        IAD 00:20
        Seattle - Washington D.C. | Mon, Nov 16 | Delta Air Lines
        THB 5,370
        31% off
        THB 7,750 THB 5,370
      • SEA 10:26
        9h 57m
        1 stop
        IAD 23:23
        Seattle - Washington D.C. | Sat, Oct 31 | American Airlines
        THB 4,660
        40% off
        THB 7,750 THB 4,660
      • SEA 10:35
        8h 57m
        1 stop
        IAD 22:32
        Seattle - Washington D.C. | Wed, Nov 11 | American Airlines
        THB 4,840
        38% off
        THB 7,750 THB 4,840
      • SEA 10:17
        9h 30m
        1 stop
        IAD 22:47
        Seattle - Washington D.C. | Tue, Oct 6 | American Airlines
        THB 4,850
        37% off
        THB 7,750 THB 4,850
      • SEA 23:10
        8h 2m
        1 stop
        IAD 10:12
        Seattle - Washington D.C. | Sun, Oct 25 | Delta Air Lines
        THB 5,170
        33% off
        THB 7,750 THB 5,170
      • SEA 05:10
        7h 38m
        1 stop
        IAD 15:48
        Seattle - Washington D.C. | Tue, Nov 3 | American Airlines
        THB 5,180
        33% off
        THB 7,750 THB 5,180
      • SEA 21:16
        30h 4m
        1 stop
        IAD 06:20
        Seattle - Washington D.C. | Fri, Oct 23 | Frontier Airlines
        THB 5,420
        30% off
        THB 7,750 THB 5,420
      • SEA 13:00
        17h 25m
        1 stop
        WAS 14:00
        Seattle - Washington D.C. | Mon, Oct 5 | Normal Airline
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Flight prices from Seattle-Tacoma International Airport to Dulles International Airport are based on the average fares across airlines for the next three months, based on Trip.com’s latest data.

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

Which month has the cheapest one-way flights from Seattle-Tacoma International Airport to Dulles International Airport?

The data is based on Trip.com data from the past 12 months and shows the average one-way fares by month from Seattle-Tacoma International Airport to Dulles International Airport.

Based on Trip.com data from the past 12 months, the cheapest one-way flights from Seattle-Tacoma International Airport to Dulles International Airport are usually in July, with an average price of THB 7,580. January sees the highest fares, around THB 17,330.

THB 17,330
THB 12,455
THB 7,580
THB 2,705
    Cheapest
  • THB 16,090
    Sep
  • THB 11,500
    Oct
  • THB 12,980
    Nov
  • THB 9,960
    Dec
  • THB 17,330
    Jan
  • THB 11,570
    Feb
  • THB 10,800
    Mar
  • THB 9,010
    Apr
  • THB 11,160
    May
  • THB 11,290
    Jun
  • THB 7,580
    Jul
  • THB 13,850
    Aug

Which day of the week has the cheapest flights from Seattle-Tacoma International Airport to Dulles International Airport?

The data is based on Trip.com data from the past 12 months and shows the average fares by each day of the week from Seattle-Tacoma International Airport to Dulles International Airport.

Based on Trip.com data from the past 12 months, the cheapest day for flights from Seattle-Tacoma International Airport to Dulles International Airport is Wednesday, with average prices lower than other days. Try to avoid departing on Sunday, as fares are typically the highest.

THB 12,720
THB 10,695
THB 8,670
THB 6,645
    Cheapest
  • THB 11,690
    Mon
  • THB 11,270
    Tue
  • THB 8,670
    Wed
  • THB 11,400
    Thu
  • THB 10,830
    Fri
  • THB 12,480
    Sat
  • THB 12,720
    Sun

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

The cheapest airline flying from Seattle-Tacoma International Airport to Dulles International Airport is Alaska Airlines (from THB 4,660) among 6 carriers operating this route. Based on Trip.com's latest 7-day flight data.

Alaska Airlines
From THB 4,660
Delta Air Lines
From THB 5,040
American Airlines
From THB 5,180
Frontier Airlines
From THB 5,420
United Airlines
From THB 6,760
Sun Country Airlines
From THB 8,610

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

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

Flight info.
Departure
Arrival
Weekly Schedule

  1. DL541

    Seattle-Tacoma International Airport

    15:55

    SEA

    4h 56m

    23:51

    IAD

    S M T W T F S
    Search

  2. AS366

    Seattle-Tacoma International Airport

    15:56

    SEA

    5h 3m

    23:59

    IAD

    S M T W T F S
    Search

  3. AS367

    Seattle-Tacoma International Airport

    21:35

    SEA

    5h 5m

    05:40

    IAD

    S - - W T - S
    Search

  4. AA585

    Seattle-Tacoma International Airport

    12:25

    SEA

    5h 17m

    Direct

    20:42

    CLT

    - - - - - - S
    Search

  5. AA5077

    Charlotte Douglas International Airport

    22:30

    CLT

    1h 28m

    Direct

    23:58

    IAD

    S M T W T F -

  6. AA858

    Seattle-Tacoma International Airport

    12:56

    SEA

    5h 4m

    Direct

    21:00

    CLT

    S M T W T F -
    Search

  7. AA5077

    Charlotte Douglas International Airport

    22:30

    CLT

    1h 28m

    Direct

    23:58

    IAD

    S M T W T F -

  8. DL810

    Seattle-Tacoma International Airport

    23:05

    SEA

    4h 21m

    Direct

    06:26

    DTW

    S M T W T F S
    Search

  9. DL1605

    Detroit Metropolitan Wayne County Airport

    08:40

    DTW

    1h 32m

    Direct

    10:12

    IAD

    - M T W T - -

  10. DL652

    Seattle-Tacoma International Airport

    23:35

    SEA

    4h 50m

    Direct

    07:25

    ATL

    S M T W T F S
    Search

  11. DL1444

    Hartsfield–Jackson Atlanta International Airport

    09:44

    ATL

    1h 46m

    Direct

    11:30

    IAD

    S M T W T - S

  12. AA1833

    Seattle-Tacoma International Airport

    12:56

    SEA

    5h 4m

    Direct

    21:00

    CLT

    S - T W T - S
    Search

  13. AA5154

    Charlotte Douglas International Airport

    11:20

    CLT

    1h 34m

    Direct

    12:54

    IAD

    S M T W T F S

  14. AA707

    Seattle-Tacoma International Airport

    10:17

    SEA

    4h 10m

    Direct

    16:27

    DFW

    S M T W T F S
    Search

  15. AA2254

    Dallas Fort Worth International Airport

    18:50

    DFW

    3h 2m

    Direct

    22:52

    IAD

    S M T W - F S

  16. DL567

    Seattle-Tacoma International Airport

    21:20

    SEA

    4h 48m

    Direct

    05:08

    ATL

    S M T W T F S
    Search

  17. DL1444

    Hartsfield–Jackson Atlanta International Airport

    09:44

    ATL

    1h 46m

    Direct

    11:30

    IAD

    S M T W T - S
Find more flights and airlines

About Seattle-Tacoma International Airport and Dulles International Airport

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

Flight distance 3,705.38km
Cheapest one-way ticket price THB 4,610
Cheapest return ticket price THB 5,900

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

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

    Seattle-Tacoma International Airport to Dulles International Airport takes about 4 hours 35 minutes on average. Actual flight time may vary depending on route, weather and air traffic.
  • There are around 6 daily flights from Seattle-Tacoma International Airport (SEA) to Dulles International Airport (IAD).
  • The earliest flight from Seattle-Tacoma International Airport to Dulles International Airport departs at 08:10, and the last departs at 23:14, with about 8 flights per day. Flight times may change, so please check the latest departure and arrival times before you travel.
  • The route from Seattle-Tacoma International Airport (SEA) to Dulles International Airport (IAD) is quite popular. Without considering departure times or holidays, tickets cost around THB 12,990 in October, the most expensive month to book this route.
  • The earliest flight departs from Seattle-Tacoma International Airport (SEA) at 08:05 and arrives in Dulles International Airport (IAD) at 16:03.
  • The latest flight departs from Seattle-Tacoma International Airport (SEA) at 21:40 and arrives in Dulles International Airport (IAD) at 05:32.
  • American Airlines is a very popular airline operating an average of 1589 flights per month.
  • One-way flights from Seattle-Tacoma International Airport to Dulles International Airport currently start from THB 4,610, and round-trip fares start from THB 5,900. The current lowest fare is a Alaska Airlines flight departing on Mon, Oct 26; prices may vary depending on availability.
  • Yes. Alaska Airlines, United Airlines and Delta Air Lines operate direct flights from Seattle-Tacoma International Airport to Dulles International Airport, with an average flight time of 4 hours 25 minutes, and around 42 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 Seattle-Tacoma International Airport to Dulles International Airport is THB 9,620. Prices may vary depending on the departure date, airline, and availability.
  • Seattle-Tacoma International Airport to Dulles 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 Seattle-Tacoma International Airport and Dulles 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 lowest estimated prices found in the last 24 hours and include all taxes and fees.

Book with no extra fees

Prices displayed on this page are all-inclusive (incl. taxes, fuel surcharges, Civil Aviation Development Fund, etc.), and all fees are shown before payment. Charges for checked baggage, meals, Wi-Fi, and other optional services may also appear in the flight cards.

Real-time pricing updates

Prices, availability, and travel information on this page have been updated within the last 24 hours, and with many routes refreshed in real time. The more popular the route, the more accurate the data.

Change & Cancellation Policy

Trip.com shows the change and cancellation rules for each ticket during the booking process, including all related fees and conditions. Please refer to 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 based on the airline’s fare rules.
Cancellation/change due to a flight schedule change:
If your flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For full details of change and cancellation policies, please refer to the customer support pages.