AirHint found the following cheapest return flights from Lisbon (LIS) to Keflavik (KEF) in September 2026 (see full year).

Return flights

29 Sep - 06 Oct	easyJet
30 Sep - 06 Oct	easyJet
23 Sep - 30 Sep	easyJet
24 Sep - 01 Oct	easyJet
30 Sep - 07 Oct	easyJet
16 Sep - 23 Sep	easyJet
28 Sep - 05 Oct	easyJet
22 Sep - 29 Sep	easyJet
01 Sep - 08 Sep	easyJet
07 Sep - 15 Sep	easyJet
29 Sep - 04 Oct	easyJet
08 Sep - 15 Sep	easyJet
26 Sep - 03 Oct	Transavia France
04 Sep - 10 Sep	easyJet
07 Sep - 16 Sep	easyJet
21 Sep - 28 Sep	easyJet
09 Sep - 16 Sep	Norwegian
30 Sep - 10 Oct	Vueling Airlines
30 Sep - 17 Oct	Vueling Airlines
26 Sep - 07 Oct	Vueling Airlines

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

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 Lisbon to Keflavik in September from 213€

Return flights