AirHint found the following cheapest return flights from Madrid (MAD) to Keflavik (KEF) in August 2025 (see full year).

Return flights

27 Aug - 02 Sep	Wizz Air
29 Aug - 03 Sep	Iberia
29 Aug - 01 Sep	Iberia
30 Aug - 11 Sep	Ryanair
26 Aug - 02 Sep	Ryanair
30 Aug - 06 Sep	Ryanair
24 Aug - 02 Sep	Wizz Air Malta
29 Aug - 08 Sep	Iberia
27 Aug - 03 Sep	Wizz Air
26 Aug - 01 Sep	Iberia Express
27 Aug - 30 Aug	Wizz Air
22 Aug - 27 Aug	Wizz Air
19 Aug - 27 Aug	Iberia
12 Aug - 20 Aug	Ryanair
14 Aug - 19 Aug	Ryanair
26 Aug - 29 Aug	Ryanair
14 Aug - 23 Aug	Ryanair
13 Aug - 20 Aug	Ryanair
19 Aug - 28 Aug	Ryanair
06 Aug - 13 Aug	Ryanair

Also check the deals for one-way flights from Madrid to Keflavik in August.

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 Madrid to Keflavik in August from $296

Return flights