Jean Tatlock, American psychiatrist and physician (d. 1944)
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.

The daughter of John Strong Perry Tatlock, a prominent Old English philologist and an expert on Geoffrey Chaucer, Tatlock was a graduate of Vassar College and the Stanford Medical School, where she studied to become a psychiatrist. Tatlock began seeing Oppenheimer in 1936, when she was a graduate student at Stanford and Oppenheimer was a professor of physics at the University of California, Berkeley. As a result of their relationship and her membership of the Communist Party, she was placed under surveillance by the FBI and her phone was tapped.

She suffered from clinical depression and committed suicide on January 4, 1944.