Efthymia (Efi) Papatheodorou (Sitaralona Trichonidos, August 26, 1938) is a Greek actress. A student of Dimitris Rontiris, she has co-starred with Elli Lampeti and was a member of the group that started the "Amore Theater".

On television, she has participated, among others, in the children's series Tou Koutiou ta Paramythia on ERT and the series Doureios Ippos on ANT1. Despite her 40-year career, an important milestone in her career was her participation in the series Sto Para 5, when her friend Irini Koumarianou suggested her for the role of Theopoula. In 2005, she participated in the Greek-American films The Sisterhood of the Traveling Pants and Opa! (Opa!), with the second being filmed in Patmos and other Greek islands.