Eleonora Gabrielian was born in Yerevan on February 22, 1929 to Tzolak Gabrielian and Zvart Cholakian. Her mother was an English teacher, her father was an electrical engineer who was repressed in 1937, rehabilitated posthumously in 1956. In 1946, Gabrielian completed secondary school and entered the Biology and Soil Faculty of the Yerevan State University, where at that time A. L. Takhtajan was teaching.