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Cheap Flights from Seattle to Washington D.C.

Hi, I've summed up all the key info for Seattle to Washington D.C. flights

Cheapest one-way

S$ 144
Frontier Airlines Sat, Oct 24

58% below next 30d avg. (S$ 339)

Cheapest return

S$ 280
Frontier Airlines Sat, Sep 26

54% below next 30d avg. (S$ 615)

Best time to book

October Cheapest month
July Peak month

Fastest flight

5h 3m Avg: 5h 1m

Recommended airlines

With a lowest one-way fare of S$ 144 , travelers can expect an average price of S$ 339 for upcoming trips, while round-trip tickets start at S$ 280 . Flights typically take around 5h 1m , but the fastest nonstop option completes the journey in just 5h 3m minutes. Flights to Washington D.C. can arrive at: Ronald Reagan Washington National Airport (DCA) and Dulles International Airport (IAD). The most common route connects Seattle-Tacoma International Airport and Dulles International Airport (SEA–IAD). To secure the best rates, booking 40 days in advance is recommended, and the cheapest travel days are Tuesday, Wednesday, and Saturday .

Updated 4d ago · This content is an AI-powered summary based on Trip.com data. Prices and availability are subject to change. Please refer to actual prices, availability, and travel conditions.

Explore the cheapest one-way and round-trip flights from Seattle to Washington D.C. over the next 90 days, with one-way fares from S$ 144 and round-trip from S$ 280. 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. | Thu, Oct 1 | Alaska Airlines
        IAD 07:02
        5h 42m
        Direct
        SEA 09:44
        Washington D.C. - Seattle | Wed, Oct 7 | Alaska Airlines
        S$ 289 S$ 629
        54% off
        54% off
        S$ 629 S$ 289
      • SEA 07:20
        5h 12m
        Direct
        DCA 15:32
        Seattle - Washington D.C. | Thu, Oct 1 | Delta Air Lines
        DCA 16:45
        5h 50m
        Direct
        SEA 19:35
        Washington D.C. - Seattle | Wed, Oct 7 | Delta Air Lines
        S$ 292 S$ 629
        54% off
        54% off
        S$ 629 S$ 292
      • SEA 07:20
        5h 12m
        Direct
        DCA 15:32
        Seattle - Washington D.C. | Fri, Oct 2 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Thu, Oct 8 | Delta Air Lines
        S$ 295 S$ 629
        53% off
        53% off
        S$ 629 S$ 295
      • SEA 14:50
        4h 59m
        Direct
        IAD 22:49
        Seattle - Washington D.C. | Tue, Oct 20 | Delta Air Lines
        IAD 07:05
        5h 51m
        Direct
        SEA 09:56
        Washington D.C. - Seattle | Sat, Oct 24 | Delta Air Lines
        S$ 295
        53% off
        S$ 629 S$ 295
      • SEA 07:20
        5h 3m
        Direct
        DCA 15:23
        Seattle - Washington D.C. | Fri, Oct 23 | Delta Air Lines
        DCA 16:45
        5h 50m
        Direct
        SEA 19:35
        Washington D.C. - Seattle | Sat, Oct 31 | Delta Air Lines
        S$ 295
        53% off
        S$ 629 S$ 295
      • SEA 16:27
        16h 44m
        1 stop
        DCA 12:11
        Seattle - Washington D.C. | Sat, Sep 26 | Frontier Airlines
        DCA 07:00
        11h 8m
        1 stop
        SEA 15:08
        Washington D.C. - Seattle | Sat, Oct 3 | Frontier Airlines
        S$ 280
        55% off
        S$ 629 S$ 280
      • 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
        S$ 292
        54% off
        S$ 629 S$ 292
      • SEA 21:45
        29h 35m
        1 stop
        IAD 06:20
        Seattle - Washington D.C. | Mon, Sep 28 | Frontier Airlines
        DCA 18:00
        24h 8m
        1 stop
        SEA 15:08
        Washington D.C. - Seattle | Mon, Oct 5 | Frontier Airlines
        S$ 292
        54% off
        S$ 629 S$ 292
      • SEA 16:27
        16h 44m
        1 stop
        DCA 12:11
        Seattle - Washington D.C. | Fri, Sep 25 | Frontier Airlines
        DCA 18:00
        24h 8m
        1 stop
        SEA 15:08
        Washington D.C. - Seattle | Mon, Sep 28 | Frontier Airlines
        S$ 586
        7% off
        S$ 629 S$ 586
      • SEA 16:27
        26h 32m
        1 stop
        DCA 21:59
        Seattle - Washington D.C. | Fri, Sep 18 | Frontier Airlines
        DCA 07:00
        11h 8m
        1 stop
        SEA 15:08
        Washington D.C. - Seattle | Sat, Sep 26 | Frontier Airlines
        S$ 591
        6% off
        S$ 629 S$ 591
      • SEA 13:00
        17h 25m
        1 stop
        WAS 14:00
        Seattle - Washington D.C. | Tue, Sep 15 | Normal Airline
        WAS 15:00
        6h
        Direct
        SEA 16:00
        Washington D.C. - Seattle | Thu, Sep 17 | Normal Airline
        Find more flights
        Find more flights
      • Cheapest nonstop
        SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Tue, Oct 6 | Alaska Airlines
        S$ 171 S$ 187
        9% off
        9% off
        S$ 187 S$ 171
      • SEA 21:36
        5h 4m
        Direct
        IAD 05:40
        Seattle - Washington D.C. | Mon, Oct 26 | Alaska Airlines
        S$ 174 S$ 187
        7% off
        7% off
        S$ 187 S$ 174
      • SEA 15:56
        5h 3m
        Direct
        IAD 23:59
        Seattle - Washington D.C. | Fri, Oct 16 | Alaska Airlines
        S$ 174 S$ 187
        7% off
        7% off
        S$ 187 S$ 174
      • SEA 21:35
        5h 5m
        Direct
        IAD 05:40
        Seattle - Washington D.C. | Fri, Oct 2 | Alaska Airlines
        S$ 175
        6% off
        S$ 187 S$ 175
      • SEA 19:41
        14h 9m
        1 stop
        DCA 12:50
        Seattle - Washington D.C. | Sat, Oct 24 | Frontier Airlines
        S$ 144
        23% off
        S$ 187 S$ 144
      • SEA 07:00
        26h 49m
        1 stop
        DCA 12:49
        Seattle - Washington D.C. | Sat, Sep 26 | Frontier Airlines
        S$ 168
        10% off
        S$ 187 S$ 168
      • SEA 07:00
        26h 49m
        1 stop
        DCA 12:49
        Seattle - Washington D.C. | Sun, Oct 4 | Frontier Airlines
        S$ 169
        10% off
        S$ 187 S$ 169
      • SEA 19:41
        23h 17m
        1 stop
        DCA 21:58
        Seattle - Washington D.C. | Tue, Nov 3 | Frontier Airlines
        S$ 169
        10% off
        S$ 187 S$ 169
      • SEA 19:41
        23h 17m
        1 stop
        DCA 21:58
        Seattle - Washington D.C. | Fri, Oct 9 | Frontier Airlines
        S$ 169
        10% off
        S$ 187 S$ 169
      • SEA 13:00
        17h 25m
        1 stop
        WAS 14:00
        Seattle - Washington D.C. | Tue, Sep 15 | Normal Airline
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        Find more flights

Flight.News
Over the past 7 days, flights from Seattle to Washington D.C. have operated an average of 26 times per day, with 26.7% on-time departure rate and 84.1% on-time arrival rate.

Which airlines are the most popular for Seattle to Washington D.C. flights?

You can choose from 2 airlines that fly from Seattle to Washington D.C., including Delta Air Lines, United Airlines, Frontier Airlines offers the lowest prices on this route.
Delta Air Lines logo Delta Air Lines
United Airlines logo United Airlines
Airlines are determined based on actual purchased flight tickets from Seattle to Washington D.C. according to previous 12 months data from Trip.com.

Flying from Seattle to Washington D.C.

The distance between Seattle and Washington D.C. is approximately 3,736.07km. It takes around 5 hours 1 minute on average to fly from Seattle to Washington D.C.. Based on Trip.com's data, travel demand peaks in July. The off-season for travel is October.

Cheapest one-way flight price S$ 144
Cheapest return ticket price S$ 280
Off-season for travel October
Peak season for travel July
Flight distance 3,736.07km
Average flight time 5 hours 1 minute
Popular airline Delta Air Lines
Frequency ～35/week
Flight statistics for the Seattle–Washington D.C. route are based on aggregated booking data from Trip.com over the past 12 months.

Trip.com Price Insights on Flights from Seattle to Washington D.C..

What is the cheapest month for one-way flights from Seattle to Washington D.C.?

The average price of one-way flights from Seattle to Washington D.C. purchased by Trip.com users by month over the past 12 months.

Based on Trip.com’s data, the cheapest month for flights from Seattle to Washington D.C. is April, with an average price of S$ 351, and the most expensive month is January, with an average price of up to S$ 603.

S$ 603
S$ 477
S$ 351
S$ 225
    Cheapest
  • S$ 403
    Sep
  • S$ 465
    Oct
  • S$ 423
    Nov
  • S$ 367
    Dec
  • S$ 603
    Jan
  • S$ 415
    Feb
  • S$ 401
    Mar
  • S$ 351
    Apr
  • S$ 352
    May
  • S$ 443
    Jun
  • S$ 402
    Jul
  • S$ 553
    Aug

Frequently Asked Questions

  • Which airlines offer the cheapest flights from Seattle to Washington D.C.?

    Based on Trip.com data, Frontier Airlines offers Cheapest nonstop one-way flights from S$ 144 (for example, SEA–DCA on Sat, Oct 24). For a Cheapest nonstop return flight, Frontier Airlines offers fares from S$ 280, departing on Sat, Sep 26 and returning on Sat, Oct 3.
  • At the moment, you can catch a direct flight from Seattle to Washington D.C. with the following airlines, including: Delta Air Lines United Airlines Selected airlines are based on historical data collected from flight bookings users made on Trip.com within the last 90 days.
  • It takes about 5 hours 1 minute to fly from Seattle (SEA) to Washington D.C. (WAS).
  • By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Seattle to Washington D.C. is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.
  • On average, 57 direct flights operate each week between Seattle and Washington D.C.. See below the schedules of the main airlines serving this route:
    United Airlines: S/M/T/W/T/F/S – UA1523 (departure at 08:26)
  • Here are some tips for finding the best flight deals from Seattle to Washington D.C. on Trip.com:
    · Be flexible with your travel dates. The cheapest flight is currently on Sat, Oct 24, with one-way fares from just S$ 144.
    · Compare airlines. Alaska Airlines currently offers the lowest fares on this route.
    · Set up a price alert to track fare changes without searching every day.
    · Check Trip.com regularly for flight deals and available promo codes.
    · Avoid peak season or book early. July is generally the busiest month for travel to Washington D.C..
    · Get exclusive promo codes on the Trip.com app.
  • The cheapest month to book a flight from Seattle to Washington D.C. is usually October, when demand is lower.
  • After crunching the numbers on our September flight calendar, it's currently cheapest to fly from Seattle to Washington D.C. on September 15, 2026 with Frontier Airlines, with prices starting at S$ 269.
  • Flights to Washington D.C. can arrive at: Ronald Reagan Washington National Airport (DCA) and Dulles International Airport (IAD). The most common route connects Seattle-Tacoma International Airport and Dulles International Airport (SEA–IAD).
  • The time difference between Washington D.C. and Seattle is 3h.
  • Tickets can only be changed or cancelled if permitted by airline policy. 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. However, 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.
  • Based on Trip.com data for flights departing in the next 30 days, the average one-way fare from Seattle to Washington D.C. is S$ 339. Fares vary by travel date, airline and availability.
  • Based on Trip.com data for travel in the next 30 days, the average round-trip fare from Seattle to Washington D.C. is S$ 615. The final price depends on the outbound and return dates, airline and fare conditions.
  • Enter Seattle and Washington D.C., choose your travel dates and passengers, then compare flights by price, duration and baggage. Select a fare, review the change and cancellation rules, enter traveller details and complete payment to receive your confirmation.
  • Frontier Airlinesare the most popular budget airlines flying from Seattle to Washington D.C.. Check baggage, seat and payment fees before comparing the final price.

Find Cheap Flights & Deals on Trip.com

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.