Jean Frances Tatlock (February 21, 1914 – January 4, 1944) was an American psychiatrist and physician. She was a member of the Communist Party of the United States of America and was a reporter and writer for the party's publication Western Worker. She is most widely known for her romantic relationship with Robert Oppenheimer, the director of the Manhattan Project's Los Alamos Laboratory during World War II. She suffered from clinical depression and committed suicide on January 4, 1944.