Until January 1, 2007, Gjern municipality is a municipality (Danish, kommune) in Aarhus County in the eastern part of the Jutland peninsula in central Denmark. The municipality covered an area of 144 km², and had a total population of 8.134 (2005). Its last mayor was Ella Porskær, a member of the Venstre (Liberal Party) political party. The site of its municipal council was the town of Gjern.