AirHint found the following cheapest one-way flights from London (LHR) to Keflavik (KEF) in December 2025 (see full year).

One-Way flights

10 Dec	Icelandair	direct
14 Dec	Icelandair	direct
04 Dec	Icelandair	direct
05 Dec	Icelandair	direct
08 Dec	Icelandair	direct
02 Dec	Icelandair	direct
12 Dec	Icelandair	direct
13 Dec	Icelandair	direct
11 Dec	Icelandair	direct
15 Dec	Icelandair	direct

Also check the deals for return 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 one-way flights from London to Keflavik in December from $94

One-Way flights