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

Return flights

29 Oct - 06 Nov	easyJet
30 Oct - 07 Nov	easyJet
31 Oct - 10 Nov	Fly Play
05 Oct - 10 Oct	Fly Play
03 Oct - 08 Oct	KLM
31 Oct - 10 Nov	Fly Play	direct
03 Oct - 06 Oct	Fly Play
12 Oct - 19 Oct	Wizz Air
31 Oct - 02 Nov	Fly Play
03 Oct - 06 Oct	Fly Play	direct
12 Oct - 19 Oct	Icelandair	direct
05 Oct - 10 Oct	TAP	direct

Also check the deals for one-way flights from Keflavik to Lisbon 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 Lisbon

Cheap car rent in Lisbon

Cheapest return flights from Keflavik to Lisbon in October from $283

Return flights