flight_takeoff SEA → LHR

Cheap Flights from Seattle to London

Compare fares on the ultra-long-haul flight from Seattle to London — a northeastbound route of about 4,786 miles, typically flown nonstop in around 10h 5m.

straighten

Distance

4,786 mi

7,702 km

schedule

Est. flight time

10h 5m

nonstop

flight

Nonstop service

Available

8 carriers

language

Time difference

8 hours ahead

London

Flying from Seattle to London

Flights from Seattle Tacoma International Airport (SEA) to London Heathrow Airport (LHR) cover roughly 4,786 miles (7,702 km) on a northeastbound heading, a nonstop flight of about 10h 5m. The route crosses 8 time zones — London is 8 hours ahead of Seattle. It's a competitive route served by 8 airlines. As an international route, make sure your passport is valid and allow extra time for customs and immigration on arrival.

Lets Fly Travel compares live fares across hundreds of airlines to find the best deal on this route — and every booking is reviewed by a real travel agent before ticketing.

Airlines on this route

Carriers that have operated nonstop service between SEA and LHR include:

flightAir France flightAmerican Airlines flightBritish Airways flightDelta Air Lines flightFinnair flightIberia Airlines flightKLM Royal Dutch Airlines flightVirgin Atlantic Airways

Airline availability and fares change over time — search your dates for current options.

Best time to fly Seattle to London

Fare patterns and travel conditions vary by season. Here's what to expect on the SEA–LHR route throughout the year.

Jan–Feb

Winter is often off-peak for London — expect fewer crowds and lower fares on the SEA–LHR route. Book early for spring breaks.

Mar–May

Spring brings pleasant weather to many destinations. Fares on the Seattle–London route can spike around school holidays — compare a few nearby dates.

Jun–Aug

Peak summer travel season. Seattle to London fares are typically at their highest. Book at least 6–8 weeks ahead and consider mid-week departures.

Sep–Oct

Shoulder season is often the sweet spot: good weather, thinner crowds, and more competitive fares on the SEA–LHR route.

Nov–Dec

Thanksgiving and Christmas drive fare spikes. If you're flying Seattle to London for the holidays, book as early as possible.

flight_land Arriving at

London Heathrow Airport

London is served by London Heathrow Airport (IATA: LHR , ICAO: EGLL). The airport is located in United Kingdom. As an international arrival, allow additional time for customs and immigration.

IATA Code

LHR

Flight Time

~10h 5m

Distance

4,786 mi

tips_and_updates Arrival tips

  • ›Check in online to save time at the airport.
  • ›Arrive 3 hours before departure.
  • ›Carry a valid passport and check visa requirements.
  • ›Compare fares across several nearby dates for best value.

Seattle to London — FAQs

How long is the flight from Seattle to London? expand_more
A nonstop flight from Seattle (SEA) to London (LHR) takes approximately 10h 5m, covering a distance of about 4786 miles (7702 km). Actual flight time varies with aircraft, routing and winds.
Which airlines fly from Seattle to London? expand_more
Airlines that have operated nonstop service on the SEA–LHR route include Air France, American Airlines, British Airways, Delta Air Lines, Finnair, Iberia Airlines, KLM Royal Dutch Airlines, Virgin Atlantic Airways. Use our search to compare current carriers, schedules and fares.
Is there a nonstop flight from Seattle to London? expand_more
Yes. The SEA–LHR route has nonstop service. Nonstop availability can vary by season and day of week, so check live results for your dates.
How far is London from Seattle? expand_more
The distance from Seattle (SEA) to London (LHR) is about 4786 miles (7702 km) as the crow flies.
What is the time difference between Seattle and London? expand_more
London is 8 hours ahead of Seattle. Factor the time change into your arrival and connection planning.
When is the best time to book flights from Seattle to London? expand_more
For international trips like Seattle to London, booking roughly 2–6 months ahead and flying mid-week (Tuesday/Wednesday) tends to surface the lowest fares. Set up a search early and compare a few date options.
Do I need a passport to fly from Seattle to London? expand_more
Yes. Flights from Seattle to London are international, so you'll need a valid passport — and possibly a visa, depending on your nationality and London's entry requirements. Check the destination's current entry rules before you travel.

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