James O'Neill (born November 15, 1847, Kilkenny, Ireland; died August 10, 1920, New London, Connecticut, United States) was an actor and the father of the American playwright Eugene O'Neill.
During his day, he was considered a promising actor, quickly working his way up the ranks to become a matinee idol. He shared stages with such renowned actors as Charlotte Cushman, Edwin Forrest, Edwin Booth, and Adelaide Neilson who said he was the best Romeo she ever had. As early as 1875, while a stock star at Hooley's Theatre in Chicago, O'Neill played the title role in a stage adaptation of Dumas' The Count of Monte Cristo. To great commercial success, he went on to play this role about 6000 times. Some, including Eugene, saw O'Neill's willingness to play the role so many times as selling out — squandering the potential of his art in order to make money.
James O'Neill later became the model for James Tyrone, the frugal, mercurial, unseeing father character in Eugene O'Neill's posthumous autobiographical play Long Day's Journey Into Night, which tells the story of the Tyrone family, which closely resembles the O'Neill family.