London (LHR) to Seattle (SEA) is about 4,790 miles and typically takes 9 h 50 min by air. It is an international route, so check passport and entry rules. Airlines with hubs at both ends are the likeliest to offer nonstops; otherwise expect a connection. Call (800) 490-3234 for live fares.
LHR to SEA at a glance
| Route | London (LHR) to Seattle (SEA) |
|---|---|
| Distance | about 4,790 miles / 7,700 km |
| Typical flight time | 9 h 50 min (estimate) |
| Time difference | 8 hours behind |
| Route type | International |
| Airlines with hubs here | Delta Air Lines, Alaska Airlines, and British Airways |
About the London to Seattle route
London to Seattle is an international trip of about 4,790 miles, so planning begins with paperwork as much as with the ticket. Your passport, any entry authorization for the United States and your connection plan matter as much as the fare.
Flight time and distance
A typical flight takes about 9 h 50 min gate to gate, with a realistic range of 9 h 35 min to 10 h 20 min depending on wind, routing and aircraft. That is an estimate based on the distance of roughly 4,790 miles (7,700 km), not a published schedule.
Seattle is 8 hours behind London on standard time, so the arrival time on your ticket will look different from the flight duration.
Among the 200 routes in our guides, LHR to SEA is longer than about 88% of them.
For comparison, London to Atlanta (LHR to ATL) is about 4,200 miles, so Seattle is a bit farther out from LHR.
The airports
London Heathrow Airport (LHR)
Heathrow is Europe's busiest airport and the home hub of British Airways, with an enormous network of transatlantic flights. Full LHR guide.
Seattle-Tacoma International Airport (SEA)
Sea-Tac is Alaska Airlines' home hub and a growing Delta gateway to Asia, which makes it a useful connecting point for Alaska, Hawaii and Pacific routes. Full SEA guide.
Nearby alternatives: around Seattle, Portland (PDX). Price all of them before you commit, especially if you have flexible dates.
Airlines on this route
No single carrier we cover has hubs at both LHR and SEA. Delta Air Lines (at SEA), Alaska Airlines (at SEA), and British Airways (at LHR) each operate a large network at one end, so many itineraries on this route connect rather than fly nonstop.
Nonstop availability on any route can shift from one season to the next, so treat this as a guide to who is likely to serve the market, not a timetable.
Common connection points
Connecting itineraries on this route often look like Delta Air Lines via Minneapolis (MSP), which adds about 610 miles (13% beyond the direct distance) or Alaska Airlines via Anchorage (ANC), which adds about 1,130 miles (24% beyond the direct distance). Choose the connection with the best weather odds for your travel month and leave a comfortable layover; our layover guide explains how much time is realistic.
Best time to fly
Seasonal factors to weigh: at SEA, july through September has the clearest weather and the heaviest demand, including cruise-season traffic to Alaska. At LHR, summer and the Christmas holiday are expensive; late autumn and early spring are often cheaper.
Ground transport
Getting to and from LHR
The Elizabeth line, Heathrow Express and Underground all reach central London in 15 to 50 minutes.
Getting to and from SEA
Link light rail runs from the terminal to downtown Seattle in roughly 40 minutes without road traffic.
Booking tips
On a long-haul trip like this one, seat selection, baggage allowance and connection time are the details that most affect comfort. Our checklist walks through each of them.
Frequently asked questions
How long is the flight from London to Seattle?
A typical LHR to SEA flight takes about 9 h 50 min, with a likely range of 9 h 35 min to 10 h 20 min. Actual time depends on wind, routing, aircraft and whether you connect.
How far is Seattle from London by air?
The great-circle distance between LHR and SEA is about 4,790 miles (7,700 km).
Which airlines fly from London to Seattle?
Delta Air Lines, Alaska Airlines, and British Airways have a major presence at LHR or SEA, and service varies by season. Ask us to check current nonstop and connecting options.
What is the time difference between London and Seattle?
Seattle is 8 hours behind London on standard time. Daylight saving time can change the gap for part of the year.
Do I need a passport to fly from London to Seattle?
Yes, international flights require a valid passport, and the United States may have additional entry or visa rules. Check the official government site before booking.
When is the best time to book LHR to SEA?
Domestic fares are often competitive one to three months ahead, while international trips benefit from more lead time. Compare several dates, since fares are priced flight by flight.
Explore related routes
More flights involving London (LHR)
- Atlanta to LondonATL to LHR
- Boston to LondonBOS to LHR
- Chicago to LondonORD to LHR
- Los Angeles to LondonLAX to LHR
- New York to LondonJFK to LHR
- Newark to LondonEWR to LHR
More flights involving Seattle (SEA)
- Atlanta to SeattleATL to SEA
- Austin to SeattleAUS to SEA
- Boston to SeattleBOS to SEA
- Detroit to SeattleDTW to SEA
- Dubai to SeattleDXB to SEA
- Houston to SeattleIAH to SEA
Last reviewed October 22, 2026. FlighTicketHub provides general information; confirm details with the airline before you travel.