Axel Madsen (May 27, 1930 – April 23, 2007) was a Danish-American biographer and journalist.
Born in Copenhagen and raised in Paris, Madsen turned from music to writing in the early 1950s, initially for the Paris edition of the New York Herald Tribune. In 1956 he moved to Canada and began working for United Press International. He moved to Hollywood in the early 1960s and began writing biographies.
Madsen wrote on topics such as cross country truck drivers and the CBS news magazine "60 minutes". He was best known for his biographies of Hollywood celebrities, fashion pioneers, and business titans. Biographies included Billy Wilder, Barbara Stanwyck, Coco Chanel, Greta Garbo, John Jacob Astor, Jacques Cousteau, Yves St. Laurent, André Malraux, Jean-Paul Sartre, Simone de Beauvoir, William C. Durant, William Wyler, and John Huston.