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

Return flights

21 Jul - 04 Aug	Aer Lingus
19 Jul - 02 Aug	Lufthansa
07 Jul - 21 Jul	Lufthansa
21 Jul - 02 Aug	Lufthansa
12 Jul - 18 Jul	Icelandair
08 Jul - 22 Jul	Alaska Airlines
16 Jul - 03 Aug	Lufthansa
07 Jul - 20 Jul	Lufthansa
15 Jul - 26 Jul	Aer Lingus
20 Jul - 03 Aug	Icelandair
11 Jul - 30 Jul	SWISS
17 Jul - 03 Aug	Finnair
08 Jul - 26 Jul	Air Canada
03 Jul - 19 Jul	Icelandair
18 Jul - 02 Aug	Lufthansa
01 Jul - 13 Jul	Icelandair
08 Jul - 12 Jul	Lufthansa

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

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 July from $896

Return flights