James Byron Warner was the younger brother of H.B. Warner and the son of Charles Warner, a prominent English stage actor, whose own father James Warner, whom J.B. was named after, was also a famous actor.
Born in Nebraska in 1895, the handsome J.B. joined the Warner family profession, though--unlike his older brother--he never appeared on the Broadway stage. He made his debut as "Jim Warner" in Knickerbocker Star Features' Crooked Road (1916) before appearing as "James Warner" in 1917 in two pictures for Falcon Features, The Secret of Black Mountain (1917) and The Lady in the Library (1917). Moving west to California, he signed with Universal Pictures in 1920 and began appearing in such horse operas as The Tough Tenderfoot (1920), billed now as "James B. Warner." In his third film at Universal, Blazing the Way (1920), he had top billing. It was his last headliner at Univeral.
After a couple of pictures for independent outfits, Warner appeared as a supporting player to western superstar Tom Mix in For Big Stakes (1922) at Fox. For Metro Pictures he headlined the western Big Stakes (1922), directed and produced by Clifford S. Elfelt. Beginning with his second film at Metro, Flaming Hearts (1922), he was billed as "J.B. Warner", a name likely to evoke his more famous brother, who was a top player in the movies and on the Broadway stage.
At Metro J.B. headlined six westerns, all of them produced by Elfelt. He then moved on to Sunset Productions, where he starred in eight low-budget westerns produced by Anthony J. Xydias, most of which were released in 1924.
Warner's career remains a "What if", as the handsome young actor never did mature into one of the "wax works" of the silent era his brother H.B. played in Billy Wilder's 1950 Hollywood classic, Sunset Blvd. (1950). Not yet 30, J.B. died on November 9, 1924, in Los Angeles, California, from tuberculosis.