In 1915, Van Sloan was the leading man with the Forsberg Players, based at the Fulton Opera House in Lancaster, Pennsylvania.

[5] Van Sloan's roles in Universal's films date from the 1930s, including Dracula (1931),[6] Frankenstein (1931), and The Mummy (1932).

[7] In the first of these, he played Professor Van Helsing,[6] the famous vampire-hunter, a role he had first taken in the successful touring production of Dracula by Hamilton Deane and John L. Balderston.

On Broadway, Van Sloan's credits included The Vigil (1948), Remote Control (1929), Dracula (1927), Lost (1927), Juarez and Maximilian (1926), Schweiger (1926), Morals (1925), Polly Preferred (1923), and The Unknown Purple (1919).

[8] In 1910, Van Sloan acted in Pinero, in Montreal, Canada, where he married the leading lady Myra Jackson,[9] with whom he had one child, Paul (born February 21, 1911, in Pennsylvania).