How long is the flight from Seattle to London?

Non-stop flights on SEA → LHR are typically around 9.5 hours. Connecting itineraries add 3–8 hours depending on the hub and layover.

Which airlines fly from Seattle to London?

The main carriers on this route are British Airways, Virgin Atlantic, American. Codeshare and one-stop options add several more — the filter panel above shows every airline in the current fare set.

When is the cheapest time to fly from Seattle to London?

Historically the lowest fares land in January, February, November. Summer (mid-June through mid-August) and the Christmas / New Year window are always peak. Mid-week departures (Tuesday–Thursday) typically beat weekend prices by 10–20%.

How far ahead should I book Seattle to London?

Six to ten weeks ahead is the sweet spot for this route. Inside three weeks, fares tend to spike as airlines sell to last-minute business travellers. Award availability often opens 10–11 months out if you're booking on miles.

Can I book directly on destination.com?

The Book button on each fare opens the airline or OTA (Trip.com, Kiwi, Expedia, Booking, Priceline, etc.) that's actually selling that ticket. You complete payment there at the same price you saw here — we never add a markup.

SEA → LHR

Seattle to London flights.

Live cached fares on Seattle (SEA) → London (LHR), refreshed every 30 minutes. Non-stop and connecting itineraries side by side — compare airlines, times and stops, then book in one click.

Flying time
~9.5h non-stop
Airlines
British Airways, Virgin Atlantic, American
Cheapest months
January, February, November

Flex dates · cheapest nearby

Loading prices…

Read our best-time-to-book guide for SEA → LHR →Target price, booking window, weekday pattern.

See 30-day price history for SEA → LHR →Median fare, lows, and best-day patterns.

No cached fares for exactly 2026-09-07 → 2026-09-14. Showing recent fares on SEA → LHR — pick a different date in the calendar above or run a live search.

Seattle → London · 10 fares12-month low · $322

Cached from Travelpayouts · filter & sort below

Showing 10 of 10 results

Cheapest
Icelandair · FI 682
OutboundSEA → LHRWed, Sep 23 · 2:00 AM· 10h 35m· 1 stop
$322
one-way
Book →
SAS · SK 938
OutboundSEA → LHRSat, Sep 5 · 10:55 PM· 11h 15m· 1 stop
ReturnLHR ← SEASat, Sep 12 · 5:40 AM· 11h 30m· 1 stop
$687
total round-trip
Book →
Icelandair · FI 684
OutboundSEA → LHRSun, Aug 2 · 6:25 AM· 10h 45m· 1 stop
ReturnLHR ← SEAMon, Aug 31 · 8:25 PM· 11h 15m· 1 stop
$690
total round-trip
Book →
Icelandair · FI 680
OutboundSEA → LHRWed, Sep 9 · 10:40 PM· 10h 45m· 1 stop
ReturnLHR ← SEAWed, Sep 16 · 8:25 PM· 11h 15m· 1 stop
$701
total round-trip
Book →
SAS · SK 938
OutboundSEA → LHRSun, Sep 13 · 10:55 PM· 11h 15m· 1 stop
ReturnLHR ← SEAFri, Sep 18 · 6:30 PM· 11h 30m· 1 stop
$702
total round-trip
Book →
Air Canada · AC 8807
OutboundSEA → LHRThu, Aug 27 · 10:00 PM· 10h 16m· 1 stop
ReturnLHR ← SEASat, Sep 5 · 9:50 AM· 12h 19m· 1 stop
$718
total round-trip
Book →
Air Canada · AC 8807
OutboundSEA → LHRThu, Aug 27 · 10:00 PM· 10h 16m· 1 stop
ReturnLHR ← SEASun, Sep 6 · 9:50 AM· 12h 19m· 1 stop
$718
total round-trip
Book →
Icelandair · FI 682
OutboundSEA → LHRMon, Oct 12 · 2:00 AM· 10h 35m· 1 stop
ReturnLHR ← SEASun, Oct 18 · 8:25 PM· 11h 15m· 1 stop
$757
total round-trip
Book →
SAS · SK 938
OutboundSEA → LHRSat, Jun 26 · 10:55 PM· 11h 15m· 1 stop
ReturnLHR ← SEASat, Jul 17 · 4:00 PM· 11h 35m· 1 stop
$899
total round-trip
Book →
Air Canada · AC 8807
OutboundSEA → LHRMon, Jun 21 · 9:55 PM· 10h 16m· 1 stop
ReturnLHR ← SEAThu, Jul 8 · 3:30 PM· 9h 55m· Non-stop
$983
total round-trip
Book →

Try a nearby airport

Thin routes often have more options from a neighbouring airport.

Portland (PDX) → London (LHR)

nearby origin

Seattle (SEA) → London (LGW)

nearby destination

Seattle (SEA) → London (STN)

nearby destination

About Seattle → London

BA + Virgin daily non-stops. SEA's tech-corridor demand keeps premium cabins tight but economy shoulder fares are PNW-friendly.

Typical non-stop flying time is around 9.5 hours. Major carriers on this route include British Airways, Virgin Atlantic, American. Fares are usually cheapest in January, February, November — book 6–10 weeks ahead and avoid school-holiday peaks (late June–August, Christmas–New Year) for the best pricing.

Month-by-month price guide: Seattle to London

Live cheapest round-trip fare cached on SEA → LHR for each of the next 12 months. Tap any month and run a live search to confirm.

Jul
No data
Aug
Low
from $690
Sep
Low
from $687
Oct
Shoulder
from $757
Nov
No data
Dec
No data
Jan
No data
Feb
No data
Mar
No data
Apr
No data
May
No data
Jun
Peak
from $899

Cheapest next 12 months: September from $687 round-trip. Run a live search →

Booking window tip

Long-haul fares are most predictable when booked 10-16 weeks ahead. Inside six weeks expect sharp increases, especially in premium cabins. If you're paying with miles, search 330+ days ahead when award inventory first loads.

Price drop alerts

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Where to stay

Once you’ve booked the flight, pick a London neighbourhood.

See where to stay in London →

Questions, answered

How long is the flight from Seattle to London?
Non-stop flights on SEA → LHR are typically around 9.5 hours. Connecting itineraries add 3–8 hours depending on the hub and layover.
Which airlines fly from Seattle to London?
The main carriers on this route are British Airways, Virgin Atlantic, American. Codeshare and one-stop options add several more — the filter panel above shows every airline in the current fare set.
When is the cheapest time to fly from Seattle to London?
Historically the lowest fares land in January, February, November. Summer (mid-June through mid-August) and the Christmas / New Year window are always peak. Mid-week departures (Tuesday–Thursday) typically beat weekend prices by 10–20%.
How far ahead should I book Seattle to London?
Six to ten weeks ahead is the sweet spot for this route. Inside three weeks, fares tend to spike as airlines sell to last-minute business travellers. Award availability often opens 10–11 months out if you're booking on miles.
Can I book directly on destination.com?
The Book button on each fare opens the airline or OTA (Trip.com, Kiwi, Expedia, Booking, Priceline, etc.) that's actually selling that ticket. You complete payment there at the same price you saw here — we never add a markup.

Other ways to reach London

If your plans are flexible on the origin, these alternate departure airports also serve London on the routes we track.

Other popular routes

Keep planning

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