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

Return flights

07 Oct - 21 Oct	SWISS
10 Oct - 14 Oct	British Airways
03 Oct - 10 Oct	British Airways
08 Oct - 13 Oct	KLM
09 Oct - 13 Oct	KLM
08 Oct - 15 Oct	KLM
11 Oct - 16 Oct	ITA Airways
02 Oct - 05 Oct	KLM
02 Oct - 08 Oct	KLM
31 Oct - 06 Nov	British Airways
01 Oct - 05 Oct	KLM
23 Oct - 02 Nov	British Airways
24 Oct - 02 Nov	KLM
31 Oct - 05 Nov	KLM
24 Oct - 03 Nov	KLM
25 Oct - 02 Nov	KLM
28 Oct - 04 Nov	Aer Lingus

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

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.

Book a cheap hotel in Keflavik

Cheap car rent in Keflavik

Cheapest return flights from London to Keflavik in October from $408

Return flights