Cheapest return flights from Seattle to London in August from $729

Best time to book flights for Seattle (SEA) to London (LHR) flights at AirHint

AirHint found the following cheapest return flights from Seattle (SEA) to London (LHR) in August 2025 (see full year).

Return flights

25 Aug - 31 Aug Scandinavian Airlines
27 Aug - 01 Sep Aer Lingus
27 Aug - 01 Sep Iberia direct
09 Aug - 20 Aug Icelandair
13 Aug - 20 Aug Icelandair
25 Aug - 31 Aug Delta direct
22 Aug - 29 Aug Icelandair
03 Aug - 19 Aug Icelandair
02 Aug - 18 Aug Icelandair
20 Aug - 25 Aug Lufthansa
21 Aug - 25 Aug Virgin Atlantic
29 Aug - 29 Sep Icelandair
20 Aug - 25 Aug Air France direct

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

Skyscanner

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