Mr. Grex of Monte Carlo is a surviving 1915 American drama silent film directed by Frank Reicher and written by Marion Fairfax and E. Phillips Oppenheim. The film stars Theodore Roberts, Dorothy Davenport, Carlyle Blackwell, James Neill, Horace B. Carpenter and Frank Elliott. The film was released on December 2, 1915, by Paramount Pictures. It is based on the novel of the same title by E. Phillips Oppenheim.