Cheapest return flights from Portland to London in September from $575

Best time to book flights for Portland (PDX) to London (STN) flights at AirHint

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

Return flights

03 Sep - 16 Sep Air Canada
07 Sep - 16 Sep Icelandair
22 Sep - 30 Sep Icelandair
10 Sep - 18 Sep Icelandair
26 Sep - 31 Oct Air Canada
24 Sep - 01 Oct Icelandair
11 Sep - 17 Sep Icelandair
14 Sep - 21 Sep Icelandair
09 Sep - 16 Sep Hawaiian Airlines
23 Sep - 29 Sep Air Canada
04 Sep - 30 Sep Air Canada
11 Sep - 19 Sep Icelandair

Also check the deals for one-way flights from Portland to London in September.

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.

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