Ares or Aris Velouchiotis (), the nom de guerre of Athanasios (Thanasis) Klaras (Latinised Claras) (, August 27, 1905 – June 16, 1945), was the most prominent leader and chief instigator of the Greek People's Liberation Army (ELAS), the military branch of the National Liberation Front (EAM), which was the major resistance organization in occupied Greece from 1942 to 1945. Aris Velouchiotis was appointed military leader of ELAS at the beginning of the Resistance Movement, by the EAM leadership, being at the same time a member of the Central Committee of the Communist Party of Greece.