Cheapest return flights from Seattle to London in August from $699

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

Return flights

19 Aug - 26 Aug Aer Lingus
26 Aug - 03 Sep Aer Lingus
16 Aug - 01 Sep Aer Lingus
09 Aug - 26 Aug Aer Lingus
19 Aug - 02 Sep Aer Lingus
31 Aug - 12 Sep Finnair
26 Aug - 07 Sep Alaska Airlines
08 Aug - 28 Aug Alaska Airlines
26 Aug - 29 Aug Air Canada
13 Aug - 04 Sep Aer Lingus
02 Aug - 08 Aug Alaska Airlines

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

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