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

Return flights

05 Mar - 17 Mar	Lufthansa
05 Mar - 16 Mar	Lufthansa
08 Mar - 16 Mar	Lufthansa
10 Mar - 17 Mar	Lufthansa
05 Mar - 12 Mar	Lufthansa
02 Mar - 16 Mar	Icelandair
05 Mar - 09 Mar	Icelandair
04 Mar - 09 Mar	Icelandair
10 Mar - 30 Apr	Icelandair
23 Mar - 30 Mar	KLM
27 Mar - 04 Apr	Lufthansa
01 Mar - 08 Mar	Lufthansa
10 Mar - 01 Apr	Icelandair
19 Mar - 03 Apr	Turkish Airlines
28 Mar - 02 Apr	Icelandair
20 Mar - 03 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 444€

Return flights