Seattle-Tacoma to London Heathrow
4786 miles great-circle distance, typically flown in 10h 02m with 8 airlines operating direct service from Seattle-Tacoma (SEA) to London Heathrow (LHR). Cheapest fares are usually in January (around $449 return), with peak prices in August (around $1347). Departures on a Tuesday tend to undercut weekend prices on this corridor.
Flying from Seattle-Tacoma
Seattle-Tacoma is Alaska Airlines' principal hub and Delta's growing Pacific Northwest base. The Link Light Rail Red Line runs from the airport's elevated station directly to Westlake in downtown Seattle in 38 minutes for $3.25 — possibly the easiest big-city transfer in the country. International long-haul has expanded sharply post-2023 with new direct service to Tokyo, Seoul, Frankfurt, London Heathrow and Auckland. Weather delays are rare; SEA is one of the most operationally reliable winter airports in the US.
Arriving in London
London Heathrow is 24 km west of central London — the deepest transatlantic hub from anywhere on the US East Coast. The Elizabeth Line and Heathrow Express both reach Paddington (15 minutes Express, 30 minutes Elizabeth) for £25 and £13.30 respectively. US carriers (American, Delta, United, JetBlue) and BA dominate the corridor. Cheapest fares from US East Coast: late January and February; peak demand is June–August.
Who flies SEA to LHR?
| Airline | IATA | Flight time | Cabin |
| Alaska Airlines | AS | 10h 02m | Economy |
| Delta Air Lines | DL | 10h 02m | Economy |
| British Airways | BA | 10h 02m | Economy |
| Lufthansa | LH | 10h 02m | Economy |
| Korean Air | KE | 10h 02m | Economy |
| ANA | NH | 10h 02m | Economy |
| Japan Airlines | JL | 10h 02m | Economy |
| Emirates | EK | 10h 02m | Economy |
8 carriers fly direct on this corridor. Frequencies vary by season — summer and winter holiday peaks see additional flights.
Best time to fly SEA→LHR
Synthesised from 12-month price aggregates. Cheapest months in green, peak in red.
Estimated baseline. Prices update on a 30-day cadence as Travelpayouts data refreshes. Cheapest day-of-week typically Tuesday.
Seattle to London FAQs
Direct flights from Seattle-Tacoma (SEA) to London Heathrow (LHR) take approximately 10h 02m for the 4786-mile journey, plus 30–60 minutes of taxi, climb and descent. Total airport-to-airport time depends on cruise winds and air-traffic queueing on approach.
January is typically the cheapest month on this route, with one-way fares from $449. August is the peak — expect prices 2–3× higher. Book 4–8 weeks ahead for best fares; last-minute prices on this corridor rise sharply inside two weeks of departure.
8 carriers operate direct service from Seattle-Tacoma (SEA) to London Heathrow (LHR): Alaska Airlines, Delta Air Lines, British Airways, Lufthansa, Korean Air and 3 more. Frequencies vary by season and carrier — Alaska Airlines typically operates the highest weekly count on this corridor.
Electronic Travel Authorisation (ETA) required for US passport holders from 2025 — apply online, £10. Always check travel.state.gov for the latest entry requirements before booking.
London Heathrow (LHR) is the primary international airport for London. Allow 30–60 minutes for the ground transfer by train, express bus, taxi or rideshare depending on traffic and time of day. See the airport's official website for current train and shuttle timetables.