Michael Kellner (born 8 May 1977) is a German politician (Alliance 90/The Greens) who has been serving as a Member of the Bundestag representing electoral constituency Uckermark – Barnim I since 2021.

In addition to his parliamentary work, Kellner has been serving as Parliamentary State Secretary at the Federal Ministry for Economic Affairs and Climate Action in the coalition government of Chancellor Olaf Scholz since 2021. In this capacity, he is also the Commissioner for Small and Medium-Sized Enterprises.

Kellner grew up in his hometown of Gera in East Germany, the son of a school principal and a polyclinic. Both parents lost their jobs after the fall of the GDR. After graduating from school, Kellner lived and worked briefly on an Israeli kibbutz. He then studied political science at the University of Potsdam from 1996 to 2002, as well as in Canterbury as an Erasmus scholarship holder and at Michigan State University, as a Fulbright scholar. In his thesis, he dealt with the relationship between the states of Berlin and Brandenburg.