William Austin Dillon (November 6, 1877 – February 10, 1966) was an American songwriter and Vaudevillian.

He is best known as the lyricist for the song "I Want A Girl (Just Like The Girl That Married Dear Old Dad)" (1911), written in collaboration with Harry Von Tilzer.,[1][2] which can be heard in Show Business (1944) and The Jolson Story (1946).

Dillon was born in Cortland, New York and performed in vaudeville with his brothers John and Harry, as well as with own act, billed as the "man of a thousand songs".

He quit the vaudeville stage around 1912 after injuries suffered in a car accident, but remained active in the entertainment world as a songwriter andtheater operator.

Dillon eventually returned to performing for troops in World War II and made television appearances.