Cheap flights from Seattle (SEA) to London (LON)

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The best prices from Seattle/Tacoma Intl to London are usually found in October or January, booked 60 days in advance, depart on a Tuesday or Monday and return on a Tuesday

How to find the cheapest flight from
Seattle (SEA) to London (LON)

All the information you need to plan the best SEA to LON flight in 2021: compare Seattle to London flight prices with the expected peak season, weather and rainfall in London.
SEA - LON
Price
$487 - $787
LON
Temperature
39.2 - 62.6 °F
LON
Precipitation
1.6 - 2.8 inches

Popular in

December

High demand for flights, 27% potential price rise

Cheapest in

October

Best time to find cheap flights, 15% potential price drop

Round-trip from

€487

From Seattle/Tacoma Intl to London All airports (LON)

One-way from

$210

One-way flight from Seattle/Tacoma Intl to London All airports (LON)

Flight route prices based on searches on Cheapflights within the last 3 days, monthly prices based on aggregated historical data.
What is the cheapest day to fly round-trip from Seattle to London?

Thursday flights are found to be more expensive to fly from Seattle to London. This shouldn’t discourage you from searching, as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to London.

How far in advance should I book a flight from Seattle to London?

When searching for a good deal, it’s best to be prepared for potential fluctuations in price. We recommend booking at least 61 days in advance, which can save you up to 75% on flights from Seattle to London compared to booking the week you need them. Waiting 61 days out may not be for everyone, so we have options available for flights within the next two weeks, with the lowest price starting at $820. For sooner than that we have options available in the next 3 days from $1,079.

What is the cheapest month to fly from Seattle to London?

October is one of the best times of the year to fly to London from Seattle. Prices for October average $575 per person but you can even find prices for as low as $416. The most expensive prices can be found in the month of December. Opting for a October flight can save you 36% on your journey compared to booking in October

When is the cheapest time to fly from Seattle to London (SEA - LON)?

One of the essential ways to save on airfare from Seattle to London is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight in the evening could potentially save you up to 6% on airfare.

Cheap flights from Seattle to London in September, October 2021

The best prices found for SEA to LON flights for September, October
17 Oct - 26 Oct
$430pp
SEA
Seattle/Tacoma Intl
Iberia
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
13 Oct - 27 Oct
$435pp
SEA
Seattle/Tacoma Intl
Iberia
 
1 STOP
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
13 Oct - 27 Oct
$445pp
SEA
Seattle/Tacoma Intl
Iberia
 
1 STOP
LHR
London Heathrow
LHR
London Heathrow
Iberia
 
1 STOP
SEA
Seattle/Tacoma Intl

Seattle/Tacoma Intl to London 2021 flight deals

Cheap flights to London from Seattle found for this year
11 Dec - 12 Jan
$418pp
SEA
Seattle/Tacoma Intl
Iberia
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
12 Dec - 9 Jan
$423pp
SEA
Seattle/Tacoma Intl
Iberia
 
1 STOP
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
11 Dec - 12 Jan
$428pp
SEA
Seattle/Tacoma Intl
Iberia
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
Iberia
 
1 STOP
SEA
Seattle/Tacoma Intl

Non-stop flights to London from Seattle

Save time with Seattle to London direct flight deals
11 Dec - 12 Jan
$418pp
SEA
Seattle/Tacoma Intl
Iberia
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
17 Oct - 26 Oct
$430pp
SEA
Seattle/Tacoma Intl
Iberia
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
Iberia
Non-Stop
SEA
Seattle/Tacoma Intl
29 Nov - 16 Jan
$443pp
SEA
Seattle/Tacoma Intl
British Airways
Non-Stop
LHR
London Heathrow
LHR
London Heathrow
British Airways
Non-Stop
SEA
Seattle/Tacoma Intl

Last minute flights from Seattle to London

Late deals on round-trip flights to London from Seattle, departing today and this week
27 Sep - 16 Oct
$733pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
   
2 STOPS
STN
London Stansted
STN
London Stansted
Multiple Airlines
   
2 STOPS
SEA
Seattle/Tacoma Intl
1 Oct - 8 Oct
$735pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
LTN
London Luton
LTN
London Luton
Multiple Airlines
 
1 STOP
SEA
Seattle/Tacoma Intl
28 Sep - 12 Oct
$744pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
   
2 STOPS
LTN
London Luton
LTN
London Luton
Multiple Airlines
   
2 STOPS
SEA
Seattle/Tacoma Intl

One-way flights to London from Seattle

The cheapest one-way flights from Seattle to London
3:03 am - 8:20 pm
Multiple Airlines
3 Stops
33h 17m
SEA - STN
Multiple Airlines
$210
Kiwi.com
3:03 am - 3:50 am
Multiple Airlines
3 Stops
40h 47m
SEA - STN
Multiple Airlines
$211
Kiwi.com
3:03 am - 7:50 pm
Multiple Airlines
3 Stops
32h 47m
SEA - STN
Multiple Airlines
$212
Kiwi.com

Related info for your journey

Useful info, stats and facts about <span class="emphasized">Seattle</span> to <span class="emphasized">London</span> flights.

Flight FAQs

From Seattle to London

What airport do you fly from for flights from Seattle to London?

If you book a flight to London from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 10 flights from Seattle/Tacoma Intl to London per day from 19 different airlines.

Which airlines flying from Seattle/Tacoma Intl to London have flexible cancellations due to COVID-19?

Delta, Virgin Atlantic, and British Airways are some of the carriers that may have flexible cancellation policies. You can use our site to filter for other airlines that may also have this kind of flexibility.

Are flight prices decreasing from Seattle to London due to COVID-19 (coronavirus)?

At this time, Cheapflights has noticed price decreases for many domestic flights due to COVID-19. Travel is not necessarily recommended at this time, and flights may be prone to cancellation: please check with local authorities in both Seattle and London for travel alerts, and be sure to review the airline's cancellation policy and travel advisories before booking. For more information, please view our post on what to know about COVID-19 (coronavirus) and travel.

Can I find flights from Seattle to London for under $500 on Cheapflights?

Yes, there are multiple flights from Seattle to London for under $500. The cheapest flight booked recently is on American Airlines for just $416, but on average you can expect to pay $456.

Are there nonstop flights from Seattle to London for under $500 on Cheapflights?

Cheapflights has at least 20 direct flights from Seattle to London under $500. A good price for a nonstop flight from Seattle to London is less than $606.

Are there last-minute flights available from Seattle to London for under $800?

There are currently 20+ open flights from Seattle to London within the next 7 days for less than $800.

What are the cheapest airlines flying from Seattle to London round-trip?

Cheapflights users have booked flights from Seattle to London round-trip from $416. Other airlines that can offer you cheap pricing are Iberia, from $418, and British Airways, from $443. Users have found that American Airlines is 27% cheaper than the other options available to this destination.

What are the most popular airlines that fly from Seattle to London?

Before booking your flight from Seattle to London check out the most popular airlines for this route: Major Airline, American Airlines or Air Canada.

What are the most popular routes from Seattle to London?

When deciding which route to take from Seattle to London consider Seattle/Tacoma Intl - London Heathrow, Seattle/Tacoma Intl - London Gatwick or Seattle/Tacoma Intl - London City as they are the most popular.

What are the most reliable airlines from Seattle to London?

Consider Alaska Airlines (93%), American Airlines (85%) or Finnair (85%) when booking your flight. These represent the most reliable airlines when flying from Seattle to London.

What are the cheapest flights from Seattle to London?

Looking at all options, your cheapest flight can be booked for $233. While the most popular route (Seattle/Tacoma Intl - London Heathrow) can be booked for $443 on average our data indicates $1,917 when flying from Seattle to London

COVID Restrictions

View COVID Travel Restrictions for London, England

Do I need a COVID test to fly to London from Seattle?

Information is based on travel restrictions from Seattle/Tacoma Intl to London

Most visitors from Seattle/Tacoma Intl need to provide a negative COVID-19 test result and/or quarantine to enter London.

COVID-19 testing requirements
Visitors from Seattle/Tacoma Intl must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to London.

Quarantine requirements
Visitors from Seattle/Tacoma Intl are not required to quarantine after entering London.

Documents
Mandatory passenger locator form - Submit the form any time in the 48 hours before arriving in the UK. Show the form when checking in your plane, train or ferry to the UK.

Managed quarantine package for Scotland - All travelers arriving directly to Scotland are required to book their Managed Quarantine Package prior to travel.

COVID-19 testing package - All travelers must book and pay for a COVID-19 Testing Package prior to travel to England and Scotland.


Do I need a test to fly back to Seattle from London?

Returning to Seattle/Tacoma Intl from London

COVID-19 testing requirements
Visitors from London must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to Seattle/Tacoma Intl.

Quarantine requirements
Visitors from London are not required to quarantine after entering Seattle/Tacoma Intl.

Hide COVID Travel Restrictions for London, England

Destination information for London

Things to know before you go - useful duration and weather info for your trip from Seattle to London.
Today's exchange rate
$1 = £0.74
Flight duration from SEA to London
9h 57m
Average temperature for September in London
68.0 °F
Avg rainfall for September in London
1.9 ″

Airports servicing Seattle

Airports servicing London

Gatwick (LGW)
Stansted (STN)
London City (LCY)
Luton (LTN)
Southend (SEN)

Top 10 airlines flying from Seattle/Tacoma Intl to London

The chart below displays the airlines Cheapflights users traveling from Seattle to London choose most often. Cheapest and average prices are based on aggregated data from the past 12 months.
Airline Cheapest Average Flexibility On-time COVID-19 safety
Finnair
$335 $853 No cancel fee 76%
Icelandair
$369 $645 No cancel fee 76%
Air Canada
$373 $633 No cancel fee 67%
Norwegian Air UK
$377 $635 No cancel fee N/A
Lufthansa
$378 $592 No cancel fee 76%
Norwegian
$403 $697 No cancel fee 74%
United Airlines
$407 $642 No cancel fee 69%
British Airways
$411 $662 No cancel fee 70%
Air France
$414 $583 No cancel fee 77%
American Airlines
$415 $735 No cancel fee 71%

Hourly flight availability from Seattle to London

See what time of day planes typically take off from Seattle towards London.
Afternoon Noon to 6 PM 54% of SEA to LON departures
Evening 6 PM to midnight 45% of SEA to LON departures
Early morning Midnight to 6 AM 1% of SEA to LON departures
Morning 6 AM to noon 0% of SEA to LON departures
Midnight
6 AM
Noon
6 PM
Weekly flight availability
from Seattle to London
See how many times per day planes take to the skies headed from Seattle to London.
Sunday
10 daily flights
Monday
10 daily flights
Tuesday
10 daily flights
Wednesday
10 daily flights
Thursday
10 daily flights
Friday
10 daily flights
Saturday
10 daily flights
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