Richard David Bach (born June 23, 1936) is an American writer widely known as the author of some of the 1970s' biggest sellers, including Jonathan Livingston Seagull (1970) and Illusions: The Adventures of a Reluctant Messiah (1977). Bach has written numerous works of fiction, and also non-fiction flight-related titles.

Most of Bach's books have been semi-autobiographical, using actual or fictionalized events from his life to illustrate his philosophy. Bach's books espouse his philosophy that our apparent physical limits and mortality are merely appearance. Bach is noted for his love of aviation and for his books related to flying in a metaphorical context. Bach has flown as a hobby since the age of 17. In late August 2012, Bach was badly injured when on approach to landing at Friday Harbor, Washington, his aircraft clipped some power lines and crashed upside down in a field.