Franz Untersteller (born 4 April 1957 in Ensheim, today a borough of Saarbrücken) is a German politician of the Green party who has been serving as State Minister of the Environment, Climate and the Energy Sector of Baden-Württemberg in the Cabinets Kretschmann I and II since 2011.

In 1982 he took part in a project of the Colombia Environment Ministry in the Cauca region, funded by a research fellowship from the Carl Duisberg Society.

In 1983 he became consultant on environmental and energy policy for the Green Party's parliamentary group in the Baden-Württemberg state parliament.

In 2006 Untersteller was elected Member of the State Parliament and acted until 2011 as deputy chairman of the Green Party's parliamentary group.

[3] In the negotiations to form another coalition government under Kretschmann's leadership following the 2021 state elections, Untersteller was a member of the working group on climate, environmental policy and energy, co-chaired by Sandra Detzer and Andreas Jung.