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

Return flights

08 Dec - 13 Dec	Ryanair
06 Dec - 08 Dec	Ryanair
01 Dec - 12 Dec	Ryanair
13 Dec - 17 Dec	Ryanair
06 Dec - 15 Dec	Ryanair
11 Dec - 12 Dec	easyJet
15 Dec - 19 Dec	easyJet
15 Dec - 21 Dec	Ryanair
10 Dec - 17 Dec	easyJet
17 Dec - 23 Dec	Lufthansa
31 Dec - 07 Jan	Ryanair
23 Dec - 01 Jan	Ryanair
22 Dec - 01 Jan	LOT
24 Dec - 01 Jan	LOT
31 Dec - 07 Jan	Icelandair	direct
31 Dec - 04 Jan	Ryanair
29 Dec - 04 Jan	Ryanair
24 Dec - 01 Jan	Icelandair	direct
27 Dec - 10 Jan	Ryanair
20 Dec - 05 Jan	Icelandair	direct

Also check the deals for one-way flights from Frankfurt 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 Frankfurt to Keflavik in December from $235

Return flights