Sigmundur Davíð Gunnlaugsson is an Icelandic politician who was the prime minister of Iceland from May 2013 until April 2016. He was also chairman of the Progressive Party from 2009 to October 2016. He was elected to the Althing as the 8th member for the Reykjavík North Constituency on 25 April 2009. He has represented the Northeast Constituency as its 1st member since 27 April 2013. Taking office at 38, he was the youngest Icelander to become prime minister.

The prime minister of Iceland is head of government of the Republic of Iceland. The prime minister is appointed formally by the president and exercises executive authority along with the cabinet subject to parliamentary support.