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

Return flights

16 Aug - 26 Aug	Aer Lingus
09 Aug - 22 Aug	Aer Lingus
09 Aug - 26 Aug	Finnair
05 Aug - 12 Aug	Air Canada
18 Aug - 02 Sep	Air Canada
16 Aug - 01 Sep	Scandinavian Airlines
24 Aug - 01 Sep	Icelandair
17 Aug - 25 Aug	Air Canada
19 Aug - 25 Aug	Air Canada
03 Aug - 19 Aug	Condor
26 Aug - 31 Aug	Air Canada
15 Aug - 26 Aug	Condor
16 Aug - 22 Aug	Air Canada
22 Aug - 12 Sep	Aer Lingus

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

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 August from $809

Return flights