AirHint found the following cheapest return flights from London (STN) to Keflavik (KEF) in December 2025 (see full year).

Return flights

09 Dec - 11 Dec	easyJet
16 Dec - 18 Dec	easyJet
02 Dec - 11 Dec	easyJet
12 Dec - 14 Dec	Ryanair
01 Dec - 04 Dec	Ryanair
01 Dec - 11 Dec	Ryanair
07 Dec - 14 Dec	Ryanair
01 Dec - 07 Dec	Ryanair
01 Dec - 06 Dec	Ryanair
02 Dec - 07 Dec	Ryanair
30 Dec - 06 Jan	Ryanair
20 Dec - 10 Jan	Ryanair
18 Dec - 06 Jan	easyJet
20 Dec - 01 Jan	Ryanair
23 Dec - 01 Jan	Ryanair
31 Dec - 12 Jan	easyJet
20 Dec - 07 Jan	Ryanair
22 Dec - 06 Jan	Ryanair
19 Dec - 01 Jan	Ryanair
30 Dec - 01 Jan	easyJet

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 $166

Return flights