James Bernard Fagan (18 May 1873 – 17 February 1933) was an Irish-born actor, theatre manager, producer and playwright active in England. After turning from the law to the stage, Fagan began his acting career, including four years from 1895 to 1899 with Herbert Beerbohm Tree's company at Her Majesty's Theatre. He then began to write plays, returning eventually to acting during World War I. In 1920, he took over London's Court Theatre as a Shakespearean playhouse and soon began to produce plays at other West End theatres. His adaptation of Treasure Island in 1922 was a hit and became an annual Christmas event.
He was the first manager of the Oxford Playhouse for several years in the 1920s. As a producer, he popularised Anton Chekhov and Seán O'Casey in Britain. In 1929, he was a director of the Festival Theatre, Cambridge. Several of his plays were adapted for film, and he moved to Hollywood in his last years.