Peter Gertner, also known as Gärtner was a German painter.

Peter Gertner received citizenship (burgher rights, Bürgerrecht) of Nuremberg on January 12, 1521, where he presumably learned from the painter Wolf Traut. He became known as a portrait painter and worked for Casimir, Margrave of Brandenburg-Kulmbach in 1527. With Casimir's widow Susanna of Bavaria, after her marriage to Otto Henry, Peter went to the court of Neuburg an der Donau, where he worked as Master Peter, Court Painter (Maister Peter, Hofmaller).

His signature was his monogram pg on a gardener's spade, which is why he is sometimes referred to as "Master PG".