AirHint found the following cheapest return flights from Portland (PDX) to London (LGW) in August 2025 (see full year).

Return flights

02 Aug - 30 Aug	Icelandair
15 Aug - 03 Sep	Icelandair
25 Aug - 04 Sep	Icelandair
12 Aug - 20 Aug	Delta
21 Aug - 28 Aug	Air France
20 Aug - 27 Aug	Icelandair
30 Aug - 09 Sep	Icelandair
30 Aug - 06 Sep	Alaska Airlines
24 Aug - 09 Sep	Icelandair
07 Aug - 14 Aug	Alaska Airlines
13 Aug - 27 Aug	Spirit Airlines
05 Aug - 11 Aug	Spirit Airlines
29 Aug - 05 Sep	Delta
29 Aug - 07 Sep	Allegiant Air
29 Aug - 14 Sep	Allegiant Air
08 Aug - 17 Aug	Spirit Airlines
13 Aug - 17 Aug	Alaska Airlines
13 Aug - 16 Aug	Alaska Airlines
13 Aug - 01 Sep	Icelandair

Also check the deals for one-way flights from Portland 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 Portland to London in August from $500

Return flights