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

Return flights

01 Dec - 08 Dec	Icelandair
05 Dec - 10 Dec	British Airways	direct
01 Dec - 08 Dec	British Airways	direct
07 Dec - 14 Dec	British Airways
04 Dec - 11 Dec	British Airways
08 Dec - 21 Dec	Icelandair
23 Dec - 17 Jan	Virgin Atlantic
10 Dec - 17 Dec	British Airways
08 Dec - 21 Dec	British Airways	direct
28 Dec - 05 Jan	American Airlines
21 Dec - 29 Dec	Alaska Airlines
23 Dec - 01 Jan	Delta
22 Dec - 06 Jan	Air Canada
26 Dec - 05 Jan	American Airlines
23 Dec - 29 Dec	Delta
28 Dec - 04 Jan	Air Canada
22 Dec - 01 Jan	American Airlines
27 Dec - 03 Jan	Air Canada
20 Dec - 10 Jan	Finnair
24 Dec - 02 Jan	Air Canada

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

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 December from $522

Return flights