Originally an actor, Leonard worked at Universal, Paramount, and for his own company, Tiffany, before joining MCM in 1925.
For most of his career he was an efficient exponent of Metros line in effulgent glamour; five times Irving Thalberg entrusted Norma Shearer to him—The Demi-Bride, Lady of Chance, The Divorcee, Let Us Be Gay, and the ill- advised O'Neill adaptation, Strange Interlude. In fact, near the end of her working life, in 1942, Shearer was reunited with him for We Were Dancing. In addition, he directed Marion Davies in The Cardboard Lover, Marianne, and Peg o’ My Heart; and Jeanette MacDonald in Maytime, The Firefly, The Girl of the Golden West, Broadway Serenade, and New Moon—enough to make him master of that MGM high key in which blonde hair seems to have caught fire. Without ever exceeding romantic splendor, Leonard was capable of bringing a fond light to high-class cheese-cake.
He also directed Garbo and Gable in Susan Lenox, a subject worthy of von Sternberg; Dancing Lady was a Joan Crawford musical, squired by Gable and Astaire; The Great Ziegfeld, a good biopic with William Powell, Myrna Loy, and Luise Rainer; a garden party Pride and Prejudice; and Ziegfeld Girl, with Judy Garland, Hedy Lamarr, and Lana Turner.
He was married first to Mae Murray, who played in Jazzmania, Fashion Row. Circe the Enchantress, and Mademoiselle Midnight.