Cheapest return flights from Seattle to London in December from 435€

AirHint found the following cheapest return flights from Seattle (SEA) to London (LHR) in December 2025 (see full year).

Return flights

02 Dec - 16 Dec Lufthansa
03 Dec - 16 Dec Lufthansa
02 Dec - 16 Dec Air France direct
03 Dec - 16 Dec Air France direct
03 Dec - 10 Dec British Airways direct
01 Dec - 08 Dec Icelandair
05 Dec - 10 Dec Lufthansa
01 Dec - 08 Dec Virgin Atlantic direct
05 Dec - 10 Dec Air France direct
11 Dec - 18 Dec British Airways
29 Dec - 24 Jan Lufthansa
28 Dec - 18 Jan Delta
31 Dec - 07 Jan British Airways
29 Dec - 24 Jan British Airways direct
23 Dec - 17 Jan Icelandair
25 Dec - 17 Jan British Airways direct
15 Dec - 07 Jan Delta direct
23 Dec - 17 Jan British Airways direct
25 Dec - 02 Jan Delta
26 Dec - 02 Jan Virgin Atlantic

Also check the deals for one-way flights from Seattle to London in December.

Skyscanner

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in London

Cheap car rent in London

Feel free to contact us with any feedback or request another flight research.