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

Return flights

20 Jul - 30 Jul	SWISS
07 Jul - 20 Jul	Aer Lingus
29 Jul - 16 Aug	Lufthansa
23 Jul - 14 Aug	Icelandair
21 Jul - 04 Aug	Alaska Airlines
25 Jul - 15 Aug	Alaska Airlines
09 Jul - 22 Jul	SWISS
22 Jul - 28 Jul	Icelandair
04 Jul - 13 Jul	Air Canada
11 Jul - 18 Jul	Alaska Airlines
13 Jul - 27 Jul	Air France
23 Jul - 28 Jul	Alaska Airlines
03 Jul - 19 Jul	Icelandair
10 Jul - 22 Jul	Alaska Airlines
30 Jul - 04 Aug	Condor
21 Jul - 02 Aug	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.

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Cheapest return flights from Seattle to London in July from 691€

Return flights