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

Return flights

06 May - 20 May	KLM
07 May - 11 May	KLM
06 May - 17 May	KLM
28 May - 07 Jun	KLM
13 May - 19 May	SWISS
06 May - 10 May	KLM
07 May - 10 May	KLM
14 May - 17 May	KLM
07 May - 18 May	KLM
20 May - 27 May	KLM
03 May - 07 May	KLM
31 May - 03 Jun	KLM
27 May - 08 Jun	KLM
13 May - 03 Jun	KLM
30 May - 07 Jun	Luxair
29 May - 12 Jun	Lufthansa
29 May - 05 Jun	Lufthansa
30 May - 04 Jun	KLM
31 May - 13 Jun	KLM
30 May - 03 Jun	KLM

Also check the deals for one-way flights from London to Keflavik in May.

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 May from $297

Return flights