Born in 1940 in Helena, Alabama, to a Baptist minister who believed acting was "the devil's work", he left home and moved to New York. After several difficult years, he enlisted in the Army, where he played football and ran track. He made All-Army in both Sports. He was offered many college scholarships, but chose to attend Texas Southern University.
After Texas Southern, he moved to California to pursue his acting career, and later continued his education at Columbia College in New York City, earning a bachelor of arts in theatre and a master's degree in cinematography. After three years of attending acting classes and acting in community plays and workshops, he landed a role in the 1968 movie Uptight directed by Jules Dassin.
Cumbuka also appeared in numerous films. He appeared as former NBA guard Oscar Robertson in the biodrama pic Maurie (1973) about the life of Maurice Stokes. In Harlem Nights (1989), he plays the toothless drunk gambler who gets shot over money. Other films include Change of Habit with Elvis Presley (1969), Blacula (1972), Trader Horn (1973), Lost in the Stars (1974), Mandingo (1975), Dr. Black, Mr. Hyde (1976), Bound for Glory (1976), The Jericho Mile (1979), Doin' Time (1985), Brewster's Millions (1985), Volunteers (1985), Out of Bounds (1986), Moving (1988) and Caged in Paradiso (1990), as well as appearances in other films.
In 2011, Cumbuka published his autobiography A Giant to Remember: The Black Actor in Hollywood. He has a son, Ji-Tu Cumbuka II, and a granddaughter, Leia Holifield.
Cumbuka died at the age of 77 on July 4, 2017, after a six-month battle with cancer.
