Naomi Jacob was born in Ripon, Yorkshire. Her father Samuel Jacob, the son of an immigrant German Jewish tailor, was the headmaster of Ripon Grammar School, and her mother was a teacher there. Her parents divorced, and Naomi attended school in Middlesbrough, where she taught briefly after graduation. She abandoned teaching for the theater and became a character actress in repertory and music hall venues. She got to know the Gielguds, du Mauriers, Henry Irving, Sarah Bernhardt, and Marie Lloyd, whose biography she would later write. She wore men’s clothes and used the names Micky, Jacob or Jake. She was politically active in the Labour Party, and ran for a seat in Parliament. She also worked for women's suffrage. After she contracted tuberculosis, she was more isolated, and became a prolific writer. She produced more than 70 books beginning with Jacob Ussher (1925), mostly novels; she also wrote plays, newspaper columns, cookbooks, and several volumes of memoirs such as Me: A Chronicle about Other People (1933). She went to live for her health at Sirmione on Lake Garda in Italy, where she was part of a British ex-patriate community along with Radclyffe Hall. During World War II, she returned to England and worked for the Ministry of Information and the Entertainments National Service Association (ENSA) in Europe. At the end of the war, she returned to Italy.