Da is a 1978 comedy play by Irish playwright Hugh Leonard. The play had its New York City premiere at the off-off-Broadway Hudson Guild Theatre in 1978, and this production transferred to Broadway shortly after the completion of its run. It was directed by Melvin Bernhardt and produced on Broadway by Lester Osterman, Marilyn Strauss and Marc Howard. It opened at the Morosco Theatre on 1 May 1978 and closed on 1 January 1980 after 697 performances.