AirHint found the following cheapest return flights from London (LCY) to Keflavik (KEF) in December 2026 (see full year).

Return flights

03 Dec - 10 Dec	Aer Lingus
03 Dec - 06 Dec	Aer Lingus
24 Dec - 28 Dec	Aer Lingus
17 Dec - 20 Dec	KLM
07 Dec - 15 Dec	Aer Lingus
10 Dec - 20 Dec	KLM
22 Dec - 29 Dec	Aer Lingus
08 Dec - 16 Dec	Aer Lingus
26 Dec - 03 Jan	KLM
21 Dec - 31 Dec	KLM
28 Dec - 01 Jan	KLM
21 Dec - 25 Dec	KLM
28 Dec - 04 Jan	KLM

Also check the deals for one-way flights from London to Keflavik 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 London to Keflavik in December from $688

Return flights