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Cheap Flights from London to Seattle

Hi, I've summed up all the key info for London to Seattle flights

Cheapest one-way

S$ 533
Icelandair Sat, Nov 7

57% below next 30d avg. (S$ 1,244)

Cheapest return

S$ 621
Icelandair Wed, Oct 21

53% below next 30d avg. (S$ 1,310)

Best time to book

September Cheapest month
July Peak month

Fastest flight

9h 55m 8m faster than avg. (10h 3m)

Recommended airlines

With a lowest one-way fare of S$ 533 , travelers can expect an average price of S$ 1,244 for upcoming trips, while round-trip tickets start at S$ 621 . Flights typically take around 10h 3m , but the fastest nonstop option completes the journey in just 9h 55m minutes. Flights to Seattle can arrive at: Seattle-Tacoma International Airport (SEA) , King County (Boeing Field) International Airport (BFI) and Kenmore Air Harbor Seaplane Base (LKE). The most common route connects Heathrow Airport and Seattle-Tacoma International Airport (LHR–SEA). To secure the best rates, booking 40 days in advance is recommended, and the cheapest travel days are Tuesday, Wednesday, and Saturday .

Updated 3d 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 London to Seattle over the next 90 days, with one-way fares from S$ 533 and round-trip from S$ 621. Based on Trip.com's latest 7-day flight data.

      • Cheapest nonstop
        LHR 11:40
        10h 20m
        Direct
        SEA 14:00
        London - Seattle | Wed, Oct 14 | Delta Air Lines
        SEA 17:30
        9h 50m
        Direct
        LHR 11:20
        Seattle - London | Tue, Oct 20 | Virgin Atlantic
        S$ 665 S$ 725
        8% off
        8% off
        S$ 725 S$ 665
      • LHR 13:05
        15h 35m
        1 stop
        SEA 20:40
        London - Seattle | Wed, Oct 21 | Icelandair
        SEA 15:40
        12h 15m
        1 stop
        LHR 11:55
        Seattle - London | Sat, Oct 24 | Icelandair
        S$ 621 S$ 725
        14% off
        14% off
        S$ 725 S$ 621
      • LHR 21:25
        28h 30m
        1 stop
        SEA 17:55
        London - Seattle | Tue, Nov 3 | Icelandair
        SEA 15:35
        12h 15m
        1 stop
        LHR 10:50
        Seattle - London | Tue, Nov 10 | Icelandair
        S$ 621 S$ 725
        14% off
        14% off
        S$ 725 S$ 621
      • LHR 21:25
        28h 30m
        1 stop
        SEA 17:55
        London - Seattle | Sat, Oct 31 | Icelandair
        SEA 15:35
        20h 55m
        1 stop
        LHR 19:30
        Seattle - London | Fri, Nov 6 | Icelandair
        S$ 631
        13% off
        S$ 725 S$ 631
      • LHR 12:20
        10h 34m
        Direct
        SEA 15:54
        London - Seattle | Mon, Nov 9 | Delta Air Lines
        SEA 06:00
        17h 45m
        1 stop
        LHR 07:45
        Seattle - London | Fri, Nov 13 | Delta Air Lines
        S$ 661
        9% off
        S$ 725 S$ 661
      • LHR 09:55
        18h 44m
        1 stop
        SEA 20:39
        London - Seattle | Thu, Sep 24 | Delta Air Lines
        SEA 21:50
        9h 45m
        Direct
        LHR 15:35
        Seattle - London | Mon, Sep 28 | Delta Air Lines
        S$ 670
        8% off
        S$ 725 S$ 670
      • LHR 08:40
        15h 55m
        1 stop
        SEA 16:35
        London - Seattle | Tue, Sep 15 | Virgin Atlantic
        SEA 09:53
        13h 17m
        1 stop
        LHR 07:10
        Seattle - London | Fri, Sep 18 | Delta Air Lines
        S$ 671
        7% off
        S$ 725 S$ 671
      • LHR 08:40
        15h 55m
        1 stop
        SEA 16:35
        London - Seattle | Wed, Sep 23 | Virgin Atlantic
        SEA 11:11
        14h 4m
        1 stop
        LHR 09:15
        Seattle - London | Wed, Sep 30 | Delta Air Lines
        S$ 671
        7% off
        S$ 725 S$ 671
      • LHR 11:45
        12h 50m
        1 stop
        SEA 16:35
        London - Seattle | Sun, Sep 20 | Virgin Atlantic
        SEA 23:08
        23h 37m
        1 stop
        LHR 06:45
        Seattle - London | Thu, Sep 24 | Virgin Atlantic
        S$ 674
        7% off
        S$ 725 S$ 674
      • LHR 08:40
        15h 55m
        1 stop
        SEA 16:35
        London - Seattle | Tue, Sep 29 | Virgin Atlantic
        SEA 08:59
        14h 16m
        1 stop
        LHR 07:15
        Seattle - London | Sun, Oct 4 | Delta Air Lines
        S$ 674
        7% off
        S$ 725 S$ 674
      • LON 13:00
        17h 25m
        1 stop
        SEA 14:00
        London - Seattle | Mon, Sep 14 | Normal Airline
        SEA 15:00
        6h
        Direct
        LON 16:00
        Seattle - London | Wed, Sep 16 | Normal Airline
        Find more flights
        Find more flights
      • Cheapest nonstop
        LHR 12:20
        10h 30m
        Direct
        SEA 14:50
        London - Seattle | Sun, Nov 8 | Virgin Atlantic
        S$ 607 S$ 669
        9% off
        9% off
        S$ 669 S$ 607
      • LHR 14:55
        9h 55m
        Direct
        SEA 16:50
        London - Seattle | Sun, Nov 8 | British Airways
        S$ 622 S$ 669
        7% off
        7% off
        S$ 669 S$ 622
      • LHR 20:35
        28h 25m
        1 stop
        SEA 17:00
        London - Seattle | Sat, Nov 7 | Icelandair
        S$ 533 S$ 669
        20% off
        20% off
        S$ 669 S$ 533
      • LGW 15:40
        13h
        1 stop
        SEA 20:40
        London - Seattle | Sun, Oct 11 | Icelandair
        S$ 544
        19% off
        S$ 669 S$ 544
      • LHR 21:25
        31h 15m
        1 stop
        SEA 20:40
        London - Seattle | Sat, Oct 24 | Icelandair
        S$ 544
        19% off
        S$ 669 S$ 544
      • LHR 13:05
        12h 50m
        1 stop
        SEA 17:55
        London - Seattle | Mon, Oct 12 | Icelandair
        S$ 552
        17% off
        S$ 669 S$ 552
      • LGW 11:55
        13h 5m
        1 stop
        SEA 17:00
        London - Seattle | Mon, Nov 9 | Icelandair
        S$ 558
        17% off
        S$ 669 S$ 558
      • LHR 12:15
        12h 45m
        1 stop
        SEA 17:00
        London - Seattle | Sun, Nov 8 | Icelandair
        S$ 560
        16% off
        S$ 669 S$ 560
      • LHR 20:35
        28h 25m
        1 stop
        SEA 17:00
        London - Seattle | Fri, Nov 6 | Icelandair
        S$ 560
        16% off
        S$ 669 S$ 560
      • LGW 11:55
        13h 5m
        1 stop
        SEA 17:00
        London - Seattle | Wed, Nov 11 | Icelandair
        S$ 591
        12% off
        S$ 669 S$ 591
      • LHR 13:05
        15h 35m
        1 stop
        SEA 20:40
        London - Seattle | Thu, Oct 22 | Icelandair
        S$ 597
        11% off
        S$ 669 S$ 597
      • LGW 15:40
        13h
        1 stop
        SEA 20:40
        London - Seattle | Sun, Oct 25 | Icelandair
        S$ 602
        10% off
        S$ 669 S$ 602
      • LON 13:00
        17h 25m
        1 stop
        SEA 14:00
        London - Seattle | Mon, Sep 14 | Normal Airline
        Find more flights
        Find more flights

Flight.News
Over the past 7 days, flights from London to Seattle have operated an average of 24 times per day, with 12.2% on-time departure rate and 90.3% on-time arrival rate.

Which airlines are the most popular for London to Seattle flights?

You can choose from 1 airlines that fly from London to Seattle, including Alaska Airlines, Icelandair offers the lowest prices on this route.
Alaska Airlines logo Alaska Airlines
Airlines are determined based on actual purchased flight tickets from London to Seattle according to previous 12 months data from Trip.com.

Flying from London to Seattle

The distance between London and Seattle is approximately 7,713.31km. It takes around 10 hours 3 minutes on average to fly from London to Seattle. Based on Trip.com's data, travel demand peaks in July. The off-season for travel is September.

Cheapest one-way flight price S$ 533
Cheapest return ticket price S$ 621
Off-season for travel September
Peak season for travel July
Flight distance 7,713.31km
Average flight time 10 hours 3 minutes
Popular airline Alaska Airlines
Frequency ～20/week
Flight statistics for the London–Seattle route are based on aggregated booking data from Trip.com over the past 12 months.

Trip.com Price Insights on Flights from London to Seattle.

What is the cheapest month for one-way flights from London to Seattle?

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

Based on Trip.com’s data, the cheapest month for flights from London to Seattle is April, with an average price of S$ 955, and the most expensive month is September, with an average price of up to S$ 1,854.

S$ 1,854
S$ 1,405
S$ 955
S$ 506
    Cheapest
  • S$ 1,854
    Sep
  • S$ 1,245
    Oct
  • S$ 1,320
    Nov
  • S$ 1,032
    Dec
  • S$ 1,318
    Jan
  • S$ 1,132
    Feb
  • S$ 1,100
    Mar
  • S$ 955
    Apr
  • S$ 962
    May
  • S$ 1,056
    Jun
  • S$ 1,338
    Jul
  • S$ 1,121
    Aug

What is the cheapest month for round-trip flights from London to Seattle?

The average price of round-trip flights from London to Seattle purchased by Trip.com users by month over the past 12 months.

Based on Trip.com’s data, the cheapest month for round-trip flights from London to Seattle is January, with an average price of S$ 738, and the most expensive month is December, with an average price of up to S$ 1,302.

S$ 1,302
S$ 1,020
S$ 738
S$ 456
    Cheapest
  • S$ 1,003
    Sep
  • S$ 1,117
    Oct
  • S$ 993
    Nov
  • S$ 1,302
    Dec
  • S$ 738
    Jan
  • S$ 973
    Feb
  • S$ 1,006
    Mar
  • S$ 1,262
    Apr
  • S$ 1,170
    May
  • S$ 1,130
    Jun
  • S$ 1,171
    Jul
  • S$ 1,212
    Aug

Frequently Asked Questions

  • Which airlines offer the cheapest flights from London to Seattle?

    Based on Trip.com data, Icelandair offers Cheapest nonstop one-way flights from S$ 533 (for example, LHR–SEA on Sat, Nov 7). For a Cheapest nonstop return flight, Icelandair offers fares from S$ 621, departing on Wed, Oct 21 and returning on Sat, Oct 24.
  • At the moment, you can catch a direct flight from London to Seattle with the following airlines, including: Alaska 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 10 hours 3 minutes to fly from London (LON) to Seattle (SEA).
  • By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from London to Seattle 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, 32 direct flights operate each week between London and Seattle. See below the schedules of the main airlines serving this route:
    Alaska Airlines: S/M/T/W/T/F/S – AS5269 (departure at 10:11)
  • Here are some tips for finding the best flight deals from London to Seattle on Trip.com:
    · Be flexible with your travel dates. The cheapest flight is currently on Sat, Nov 7, with one-way fares from just S$ 533.
    · Compare airlines. Virgin Atlantic 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 Seattle.
    · Get exclusive promo codes on the Trip.com app.
  • The cheapest month to book a flight from London to Seattle is usually September, when demand is lower.
  • After crunching the numbers on our September flight calendar, it's currently cheapest to fly from London to Seattle on September 29, 2026 with Icelandair, with prices starting at S$ 561.
  • Flights to Seattle can arrive at: Seattle-Tacoma International Airport (SEA), King County (Boeing Field) International Airport (BFI) and Kenmore Air Harbor Seaplane Base (LKE). The most common route connects Heathrow Airport and Seattle-Tacoma International Airport (LHR–SEA).
  • The time difference between Seattle and London is 8h.
  • 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 London to Seattle is S$ 1,244. 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 London to Seattle is S$ 1,310. The final price depends on the outbound and return dates, airline and fare conditions.
  • Enter London and Seattle, 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.

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.