AirHint found the following cheapest return flights from Seattle (SEA) to London (STN) in March 2026 (see full year).

Return flights

03 Mar - 08 Mar	Icelandair
02 Mar - 31 Mar	Icelandair
03 Mar - 07 Mar	Lufthansa
02 Mar - 07 Mar	Icelandair
11 Mar - 26 Mar	Icelandair
05 Mar - 09 Mar	Icelandair
17 Mar - 08 Apr	Turkish Airlines
26 Mar - 07 Apr	Turkish Airlines
03 Mar - 13 Mar	Icelandair
12 Mar - 18 Mar	Condor
10 Mar - 24 Mar	Icelandair
09 Mar - 24 Mar	Icelandair
25 Mar - 12 Apr	Turkish Airlines
18 Mar - 15 Apr	Alaska Airlines
21 Mar - 01 Apr	Turkish Airlines

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

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

Cheapest return flights from Seattle to London in March from $563

Return flights