Cheapest return flights from Portland to London in September from $541

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

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

Return flights

26 Sep - 05 Oct Icelandair
11 Sep - 16 Sep Icelandair
12 Sep - 19 Sep Icelandair
02 Sep - 09 Sep British Airways
17 Sep - 24 Sep Icelandair
04 Sep - 30 Sep Air Canada
07 Sep - 14 Sep British Airways direct
01 Sep - 08 Sep United
04 Sep - 30 Sep Iberia direct
01 Sep - 08 Sep British Airways direct
27 Sep - 04 Oct British Airways direct
26 Sep - 05 Oct American Airlines direct

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

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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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