American film actor, director, and writer, best known today for playing a frantic dope addict in the 1936 low-budget exploitation film Tell Your Children (later titled Reefer Madness), yelling “Play it faster, play it faster!” to a piano-playing girl (Lillian Miles).
He started his film career performing in choruses and working as a stunt double before gradually winning larger roles, mostly in B pictures.
O’Brien was best known to movie audiences in the 1940s as the hero of the famous Metro-Goldwyn-Mayer comedy short film series Pete Smith Specialties narrated by Pete Smith. O’Brien wrote and directed many of these subjects under the name David Barclay. O’Brien also had a small dancing part with Bebe Daniels in the Busby Berkeley musical 42nd Street (1933).
He also appeared in many low-budget Westerns, often billed as “Tex” O’Brien, alluding to his home state. One of his later roles was in the MGM musical version of Kiss Me, Kate (1953).
As a writer for The Red Skelton Show, O’Brien shared an Emmy Award for Outstanding Writing for a Comedy Series in 1961 and shared a nomination for the same award in 1963.
O’Brien married one of his co-stars of Reefer Madness, Dorothy Short, in 1936, but they divorced in 1954 after having two children. In 1955, he married Nancy O’Brien and had three more children.
A very keen yachtsman and sailor, he died on 8 November 1969 aged 57 of a heart attack aboard a 60-foot sloop named The White Cloud while competing in a yachting race off the California coast near Catalina Island.

Link to Wikipedia biography