Simone Rethel-Heesters (born 15 June 1949 in Herrsching am Ammersee, Bavaria) is a German actress and writer.

After she completed schooling, she took part to Hanna Burgwitz's acting lessons and made her stage debut during her formation by playing in Joseph von Eichendorff's Die Freier at the Bayerisches Staatsschauspiel [de] in Munich in 1966 under the direction of Axel von Ambesser, who had discovered her and later granted her several stage and television roles.

Rethel mainly appeared in boulevard theatre plays and had roles in numerous television series such as Der Kommissar, Derrick, The Old Fox, Schöne Ferien and Diese Drombuschs.

Since early 2005, she has been an ambassador of Altern in Würde and has raised awareness about Alzheimer's disease.

In early 2010, she published her book Sag nie, du bist zu alt, in which she criticises negative view of society on ageing.