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Dulles International Airport to Seattle Tacoma Intl. Airport flight

Explore the cheapest one-way and round-trip flights from Dulles International Airport to Seattle Tacoma Intl. Airport over the next 90 days, with one-way fares from $144 and round-trip from $238. Based on Trip.com's latest 7-day flight data.

      • Cheapest nonstop
        IAD 7:25 AM
        5h 40m
        Nonstop
        SEA 10:05 AM
        Washington D.C. - Seattle | Wed, Oct 14 | Delta Air Lines
        SEA 7:20 AM
        5h 3m
        Nonstop
        DCA 3:23 PM
        Seattle - Washington D.C. | Mon, Oct 19 | Delta Air Lines
        $238 $361
        34% off
        34% off
        $361 $238
      • IAD 7:02 AM
        5h 42m
        Nonstop
        SEA 9:44 AM
        Washington D.C. - Seattle | Wed, Oct 14 | Alaska Airlines
        SEA 1:49 PM
        5h 10m
        Nonstop
        DCA 9:59 PM
        Seattle - Washington D.C. | Mon, Oct 19 | Alaska Airlines
        $259 $361
        28% off
        28% off
        $361 $259
      • IAD 7:00 AM
        5h 37m
        Nonstop
        SEA 9:37 AM
        Washington D.C. - Seattle | Sun, Oct 4 | Alaska Airlines
        SEA 3:56 PM
        5h 3m
        Nonstop
        IAD 11:59 PM
        Seattle - Washington D.C. | Wed, Oct 7 | Alaska Airlines
        $279 $361
        23% off
        23% off
        $361 $279
      • IAD 5:57 PM
        5h 47m
        Nonstop
        SEA 8:44 PM
        Washington D.C. - Seattle | Sun, Sep 27 | Alaska Airlines
        SEA 9:35 PM
        5h 5m
        Nonstop
        IAD 5:40 AM
        Seattle - Washington D.C. | Tue, Sep 29 | Alaska Airlines
        $280
        22% off
        $361 $280
      • IAD 7:02 AM
        5h 42m
        Nonstop
        SEA 9:44 AM
        Washington D.C. - Seattle | Thu, Oct 15 | Alaska Airlines
        SEA 9:36 PM
        5h 4m
        Nonstop
        IAD 5:40 AM
        Seattle - Washington D.C. | Tue, Oct 20 | Alaska Airlines
        $289
        20% off
        $361 $289
      • IAD 6:00 AM
        30h 42m
        1 stop
        SEA 9:42 AM
        Washington D.C. - Seattle | Thu, Oct 1 | Frontier Airlines
        SEA 4:27 PM
        16h 44m
        1 stop
        DCA 12:11 PM
        Seattle - Washington D.C. | Thu, Oct 8 | Frontier Airlines
        $268
        26% off
        $361 $268
      • IAD 7:00 AM
        5h 37m
        Nonstop
        SEA 9:37 AM
        Washington D.C. - Seattle | Thu, Oct 1 | Alaska Airlines
        SEA 4:27 PM
        16h 44m
        1 stop
        DCA 12:11 PM
        Seattle - Washington D.C. | Thu, Oct 8 | Frontier Airlines
        $270
        25% off
        $361 $270
      • IAD 7:00 AM
        5h 37m
        Nonstop
        SEA 9:37 AM
        Washington D.C. - Seattle | Tue, Sep 29 | Alaska Airlines
        SEA 7:41 PM
        23h 17m
        1 stop
        DCA 9:58 PM
        Seattle - Washington D.C. | Sun, Oct 4 | Frontier Airlines
        $270
        25% off
        $361 $270
      • IAD 7:25 AM
        5h 40m
        Nonstop
        SEA 10:05 AM
        Washington D.C. - Seattle | Thu, Oct 1 | Delta Air Lines
        SEA 4:27 PM
        16h 44m
        1 stop
        DCA 12:11 PM
        Seattle - Washington D.C. | Thu, Oct 8 | Frontier Airlines
        $275
        24% off
        $361 $275
      • IAD 7:00 AM
        5h 37m
        Nonstop
        SEA 9:37 AM
        Washington D.C. - Seattle | Fri, Oct 9 | Alaska Airlines
        SEA 4:27 PM
        26h 32m
        1 stop
        DCA 9:59 PM
        Seattle - Washington D.C. | Wed, Oct 14 | Frontier Airlines
        $289
        20% off
        $361 $289
      • IAD 5:57 PM
        5h 47m
        Nonstop
        SEA 8:44 PM
        Washington D.C. - Seattle | Thu, Oct 8 | Alaska Airlines
        SEA 4:27 PM
        26h 32m
        1 stop
        DCA 9:59 PM
        Seattle - Washington D.C. | Wed, Oct 14 | Frontier Airlines
        $289
        20% off
        $361 $289
      • IAD 6:00 AM
        29h 58m
        1 stop
        SEA 8:58 AM
        Washington D.C. - Seattle | Mon, Oct 26 | Frontier Airlines
        SEA 9:16 PM
        30h 4m
        1 stop
        IAD 6:20 AM
        Seattle - Washington D.C. | Wed, Oct 28 | Frontier Airlines
        $292
        19% off
        $361 $292
      • WAS 1:00 PM
        17h 25m
        1 stop
        SEA 2:00 PM
        Washington D.C. - Seattle | Fri, Sep 25 | Normal Airline
        SEA 3:00 PM
        6h
        Nonstop
        WAS 4:00 PM
        Seattle - Washington D.C. | Sun, Sep 27 | Normal Airline
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      • Cheapest nonstop
        IAD 5:46 PM
        5h 47m
        Nonstop
        SEA 8:33 PM
        Washington D.C. - Seattle | Mon, Sep 28 | Alaska Airlines
        $145 $196
        26% off
        26% off
        $196 $145
      • IAD 7:25 AM
        5h 40m
        Nonstop
        SEA 10:05 AM
        Washington D.C. - Seattle | Fri, Oct 2 | Delta Air Lines
        $145 $196
        26% off
        26% off
        $196 $145
      • IAD 9:03 AM
        5h 36m
        Nonstop
        SEA 11:39 AM
        Washington D.C. - Seattle | Fri, Oct 2 | Alaska Airlines
        $149 $196
        24% off
        24% off
        $196 $149
      • IAD 7:10 AM
        5h 40m
        Nonstop
        SEA 9:50 AM
        Washington D.C. - Seattle | Wed, Oct 7 | Delta Air Lines
        $151
        23% off
        $196 $151
      • IAD 5:57 PM
        5h 47m
        Nonstop
        SEA 8:44 PM
        Washington D.C. - Seattle | Thu, Sep 24 | Alaska Airlines
        $158
        19% off
        $196 $158
      • IAD 6:00 AM
        30h 42m
        1 stop
        SEA 9:42 AM
        Washington D.C. - Seattle | Wed, Oct 14 | Frontier Airlines
        $144
        27% off
        $196 $144
      • IAD 7:57 AM
        10h 20m
        1 stop
        SEA 3:17 PM
        Washington D.C. - Seattle | Fri, Oct 2 | American Airlines
        $145
        26% off
        $196 $145
      • IAD 6:00 AM
        30h 42m
        1 stop
        SEA 9:42 AM
        Washington D.C. - Seattle | Mon, Oct 12 | Frontier Airlines
        $149
        24% off
        $196 $149
      • IAD 5:01 AM
        10h 17m
        1 stop
        SEA 12:18 PM
        Washington D.C. - Seattle | Sat, Oct 24 | American Airlines
        $149
        24% off
        $196 $149
      • IAD 6:00 AM
        30h 42m
        1 stop
        SEA 9:42 AM
        Washington D.C. - Seattle | Thu, Oct 15 | Frontier Airlines
        $149
        24% off
        $196 $149
      • IAD 6:00 AM
        30h 42m
        1 stop
        SEA 9:42 AM
        Washington D.C. - Seattle | Fri, Oct 9 | Frontier Airlines
        $153
        22% off
        $196 $153
      • IAD 12:29 PM
        9h 35m
        1 stop
        SEA 7:04 PM
        Washington D.C. - Seattle | Sat, Oct 24 | Delta Air Lines
        $156
        20% off
        $196 $156
      • WAS 1:00 PM
        17h 25m
        1 stop
        SEA 2:00 PM
        Washington D.C. - Seattle | Fri, Sep 25 | Normal Airline
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Displayed flight fares from Dulles International Airport to Seattle Tacoma Intl. Airport are based on average prices across airlines for the next 3 months, according to the latest Trip.com database.

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

What is the cheapest month for one-way flights from Dulles International Airport to Seattle Tacoma Intl. Airport?

Data is based on average one-way flight prices from Dulles International Airport to Seattle Tacoma Intl. Airport in Trip.com's database over the past 12 months.

Based on Trip.com’s data from the past 12 months, if you’re looking for a low-cost one-way ticket from Dulles International Airport to Seattle Tacoma Intl. Airport, the best time to buy is in March, with an average price of $217. You’ll want to avoid December, when the average price can reach as high as $491.

$491
$354
$217
$80
    Cheapest
  • $267
    Sep
  • $294
    Oct
  • $311
    Nov
  • $491
    Dec
  • $282
    Jan
  • $264
    Feb
  • $217
    Mar
  • $230
    Apr
  • $330
    May
  • $259
    Jun
  • $362
    Jul
  • $331
    Aug

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

The data is based on the past 12 months and shows the average ticket prices from Dulles International Airport to Seattle Tacoma Intl. 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 day to depart from Dulles International Airport to Seattle Tacoma Intl. Airport is Sunday, with average fares typically lower than other days. You’ll want to avoid flying on Friday, as ticket prices are usually the highest that day.

$413
$340
$267
$194
    Cheapest
  • $298
    Mon
  • $271
    Tue
  • $302
    Wed
  • $341
    Thu
  • $413
    Fri
  • $326
    Sat
  • $267
    Sun

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

The cheapest airline flying from Dulles International Airport to Seattle Tacoma Intl. Airport is Frontier Airlines (from $136) among 7 carriers operating this route. Based on Trip.com's latest 7-day flight data.

Frontier Airlines
From $136
Delta Air Lines
From $151
Alaska Airlines
From $166
American Airlines
From $195
United Airlines
From $200
Air Canada
From $216
Sun Country Airlines
From $226

Find more flights and airlines

What is the flight schedule from Dulles International Airport to Seattle Tacoma Intl. 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 AM

    IAD

    5h 48m

    12:48 PM

    SEA

    S M T W T F S
    Search

  2. DL1015

    Dulles International Airport

    7:05 AM

    IAD

    6h

    10:05 AM

    SEA

    S M T W T F S
    Search

  3. AS1574

    Dulles International Airport

    7:00 AM

    IAD

    5h 37m

    9:37 AM

    SEA

    S M T W T F S
    Search

  4. AS375

    Dulles International Airport

    9:03 AM

    IAD

    5h 36m

    11:39 AM

    SEA

    S M T W T F S
    Search

  5. AS737

    Dulles International Airport

    5:57 PM

    IAD

    5h 47m

    8:44 PM

    SEA

    S M T W T F S
    Search

  6. UA1128

    Dulles International Airport

    5:35 PM

    IAD

    5h 35m

    8:10 PM

    SEA

    S M T W T F S
    Search

  7. DL2127

    Dulles International Airport

    6:00 AM

    IAD

    1h 54m

    Nonstop

    7:54 AM

    ATL

    S M T W T F S
    Search

  8. DL629

    Hartsfield–Jackson Atlanta International Airport

    12:15 PM

    ATL

    5h 35m

    Nonstop

    2:50 PM

    SEA

    S M T W T F S

  9. F94409

    Dulles International Airport

    8:39 PM

    IAD

    2h 11m

    Nonstop

    10:50 PM

    ATL

    S M T W T F S
    Search

  10. F91449

    Hartsfield–Jackson Atlanta International Airport

    6:41 AM

    ATL

    3h 23m

    Nonstop

    8:04 AM

    DEN

    S M T W T F S

  11. F91175

    Denver International Airport

    1:07 PM

    DEN

    3h 5m

    Nonstop

    3:12 PM

    SEA

    S M T W T F S

  12. F94277

    Dulles International Airport

    6:30 AM

    IAD

    4h 57m

    Nonstop

    8:27 AM

    LAS

    S M T W T F S
    Search

  13. F94203

    Harry Reid Intl. Airport

    4:39 PM

    LAS

    3h 1m

    Nonstop

    7:40 PM

    SEA

    S - - - T - -

  14. F94277

    Dulles International Airport

    6:30 AM

    IAD

    4h 57m

    Nonstop

    8:27 AM

    LAS

    S M T W T F S
    Search

  15. F92407

    Harry Reid Intl. Airport

    10:03 AM

    LAS

    2h 59m

    Nonstop

    1:02 PM

    SEA

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

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

Flight distance 3,705.38 km
Cheapest one-way ticket price $144
Cheapest return ticket price $238

FAQs for Dulles International Airport to Seattle Tacoma Intl. Airport Flights

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

    Dulles International Airport to Seattle Tacoma Intl. 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 Intl. Airport (SEA).
  • The earliest flight from Dulles International Airport to Seattle Tacoma Intl. Airport departs at 07:00, and the last departs at 17:57, with about 6 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 Intl. Airport (SEA) is quite popular. Without considering departure times or holidays, tickets cost around $511 in September, the most expensive month to book this route.
  • The earliest flight departs from Dulles International Airport (IAD) at 06:25 and arrives in Seattle Tacoma Intl. Airport (SEA) at 09:08.
  • The latest flight departs from Dulles International Airport (IAD) at 19:41 and arrives in Seattle Tacoma Intl. Airport (SEA) at 22:30.
    • The distance from Seattle-Tacoma International Airport to downtown is about 17 km. It takes about 30 minutes by taxi.
  • 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 Intl. Airport currently start from $144, and round-trip fares start from $238. The current lowest fare is a Frontier Airlines flight departing on Wed, Oct 14; 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 Intl. 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 Intl. Airport is $269. Prices may vary depending on the departure date, airline, and availability.
  • Dulles International Airport to Seattle Tacoma Intl. Airport operates around 29 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 Intl. 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 estimated lowest price and include all taxes and fees found in the last 24 hours.

Book with no extra fees

Prices displayed in this page are all-inclusive prices (incl. taxes, fuel surcharge, civil aviation development fund, etc) with all fees confirmed before payment. Fees for luggage, meals, WLAN, 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 were updated within last 24 hours—even in real-time. The more popular the route, the more precise the data.

Change & Cancellation Policy

Trip.com displays flight cancellation and change policies for each flight ticket during the booking process, including fees and applicable conditions. Please check the following scenarios:
Voluntary cancellation/change:
To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy.
Cancellation/change due to a flight schedule change:
If the flight has been rescheduled 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 check the customer support pages.