Cheapest return flights from Keflavik to Lisbon in May from $483

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

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.