Ekaterina Alekseevna Feoktistova (also Alekseyevna) (Russian:Екатерина Алексеевна Феоктистова, 18 March 1915 – 5 January 1987) was a Ukrainian Soviet chemist, engineer, physicist and explosives expert. She worked on the Soviet atomic bomb project from 1947 until her retirement, leading a laboratory from 1952.