Serra de São Mamede is a mountain range in Portalegre District, Portugal. This range is named after Saint Mammes. Together with the Serra de Arraiolos, the Serra de São Mamede is one of the few places in the Alentejo region where there might be snow in the winter.

Saint Mammes of Caesarea was a child-martyr of the 3rd century, who was martyred at Caesarea. His parents, Theodotus and Rufina, were also martyred.