Hornnes is a former municipality in the old Aust-Agder county in Norway. Hornnes was located in what is now the present-day municipality of Evje og Hornnes in the traditional district of Setesdal in Agder county. The 378-square-kilometre (146 sq mi) municipality of Hornnes existed from 1886 until 1960. The administrative centre was the village of Hornnes where the Hornnes Church is located.