He is an acting teacher.
He and his wife, the former Erma Dean Gibbons, have one son.
Appeared as a guest star on several episodes of McCloud (1970), which starred his long-time friend Dennis Weaver, whom he originally urged to go into show business. Also very close friends with Pat Hingle and Logan Ramsey.
Was named "Outstanding Alumnus" at Missouri Southern State University in Joplin, Missouri in 2005. Lonny graduated from Joplin High School and, in 1940, Joplin Junior College, Missouri Southern's predecessor institution.
Reliable, gruff-toned character actor on stage screen and TV for over six decades who, following service in the South Pacific during World War II, graduated from the University of Oklahoma, then moved to New York City where he landed the lead in "Come Back, Little Sheba".
Since the 1970s was artistic director of the Group Repertory Theatre (GRT) in Burbank, California. The name of the company was eventually changed to Lonny Chapman's Group Repertory Theatre in honor of the actor.
Had a starring role in the short-lived series For the People (1965).
With the late Curt Conway, he operated the Fishkill Summer Playhouse in upper New York state for many years, where such stars as Barbra Streisand, Dustin Hoffman and Robert Duvall got their start. Hoffman got his Equity card there with a production of "The Diary of Anne Frank". Streisand did her first musical there playing Hortense in "The Boyfriend" and a legit role in the play "Separate Tables".
A member of The Actors' Studio, it was there that he met and became life-long friends with Mark Rydell, Martin Landau, Salome Jens, R.G. Armstrong, Pat Hingle and Logan Ramsey.
Born in Oklahoma, raised in Missouri.
A memorial was held for Lonny on December 4, 2007, at his Group Repertory Theatre in North Hollywood. Among those in attendance were actress Barbara Bain, director Mark Rydell, actor Jim Antonio and his brother, actor/director Lou Antonio. Sean Penn and Jennifer Tilly, plus nonagenarians Karl Malden and R.G. Armstrong gave their respective tributes via written notes of appreciation.