Ærø Municipality (Danish: Ærø Kommune) is a kommune occupying the 88 km island of Ærø in Denmark in the Region of Southern Denmark as of 1 January 2007, and in 2006 in Funen County. The municipality also encompasses Birkholm and the uninhabited islands Lilleø, Dejrø and Halmø.
The first mayor of Ærø (2006–09;2014–17) was Jørgen Otto Jørgensen (born 21 December 1950, Marstal) a member of the Social Democrats (Socialdemokraterne) political party, until 2005 mayor of Ærøskøbing Municipality. As of 1 January 2022 the mayor is Peter Hansted (born 12 January 1956, Lyngby) representing the Social Democrats. The most populous town is Marstal and the seat of the municipal council is Ærøskøbing.