Antonio Franz Theus "Tonio" Selmair-Selwart (June 9, 1896 – November 2, 2002) was a German actor and stage performer.

His luck panned out in New York City, where he landed the lead part in Lawrence Langner's and Armina Marshall's play The Pursuit of Happiness for the Theatre Guild in 1930.

The comedy proved to be his first big success in America, running from 1933 to 1934, and made him, as he often put it, "a matinee idol for a whole year!"

Other titles include: Anzio (1968) by Edward Dmytryk, his last Hollywood film appearance; The North Star (1943), directed by Lewis Milestone with a script by playwright Lillian Hellman, with Erich von Stroheim; Edge of Darkness (1943), also by Milestone, his first film role, where he played his first film German soldier role, opposite Judith Anderson; Wilson (1944), where he played the German ambassador to Washington, D.C. during World War I, Count von Bernstorff; The Cross of Lorraine (1943), with Gene Kelly; The Hitler Gang (1944), playing the Nazi official Alfred Rosenberg and Romanoff and Juliet (1961), written, directed and starring Peter Ustinov, and an Italian-American adaptation of Homer's Iliad, Helen of Troy (1956), directed by Robert Wise, with Rossanna Podesta, Jacques Sernas, and in two featured roles, Selwart played opposite a then almost unknown Brigitte Bardot, in 1956.

He also made a brief speaking part appearance in Luchino Visconti's Italian film Senso (1954), at the beginning opera house scene, as an Austrian officer.

Starting from the late 1940s until the 1950s and 1960s, he also appeared on American television, making guest appearances in drama programs, including The Fifth Column for Buick-Electra Playhouse on CBS in 1960, playing an almost-deaf Nazi officer in a group of fifth columnists operating behind the lines in Madrid during the Spanish Civil War in the 1930s (the program was adapted from a story by Ernest Hemingway and directed by John Frankenheimer).

His performances included: The Pursuit of Happiness (touring with it across the U.S. and England), Candle in the Wind by Maxwell Anderson with Helen Hayes (where he played his first German Nazi officer role, a type of character he came to specialize in), The Laughing Woman with Helen Menken, Autumn Crocus, Seeds in the Wind, Liliom by Ferenc Molnár (in which Selwart played the title role), and The Hidden River in 1957, among many others.

As a member of Eva Le Gallienne's Civic Repertory he appeared in Peter Pan, Alice in Wonderland, and Frank Wedekind's Spring's Awakening—a tragedy about adolescence which he also directed.