Mary Antin (June 13, 1881 – May 15, 1949) was an American author and immigration rights activist.
Born to a Jewish family in Polotsk, she immigrated to the Boston area with her mother and siblings in 1894, moving from Chelsea to Ward 8 in Boston's South End, a notorious slum, as the venue of her father's store changed. She married Amadeus William Grabau, a geologist, in 1901, and moved to New York City where she attended Teachers College of Columbia University and Barnard College. Antin is best known for her 1912 autobiography The Promised Land, which describes her public school education and assimilation into American culture, as well as life for Jews in Czarist Russia. After its publication, Antin lectured on her immigrant experience to many audiences across the country, and became a major supporter for Theodore Roosevelt and his Progressive Party.
During World War I, while she campaigned for the Allied cause, her husband's pro-German activities precipitated their separation and her physical breakdown. Amadeus was forced to leave his post at Columbia University to work in China, where he was was one of the pioneers in Chinese geology. She was never physically strong enough to visit him there. During the war, Amadeus was interned by the Japanese and died shortly after his release in 1946. Mary died of cancer, May 15, 1949.