Harlem-born Clarence Williams III was raised by his grandparents, both professional musicians; his father was a musician as well (via New York Daily News). He made his acting debut in 1958 in a play produced at the Harlem YMCA, which happened to star Cicely Tyson, according to The Hollywood Reporter. Following a stint in the military, he returned to the stage and was nominated for a Tony for the play "Slow Dance on the Killing Ground." From there, it wasn't long before he was tapped for "Mod Squad." Some of his other TV appearances included "Twin Peaks," "Star Trek: Deep Space Nine," "Law & Order," and "Everybody Hates Chris," per IMDb.

The news of Williams' death was met with shock and sorrow from both fans and former colleagues. Writer-director-producer Lee Daniels tweeted, "An extraordinary actor. Revolutionary. Ahead of his time. What an honor to work with this man on THE BUTLER. Rest in Power." 

Musician Lenny Kravitz wrote a heartfelt tribute: "When I was a kid growing up in NYC Clarence Williams III was a face on TV that I identified with and that inspired me. From the Mod Squad, to Purple Rain and Sugar Hill, he always performed with dynamic energy. Rest in power, king." 

Kellie Martin, who worked with Williams on the miniseries "Mystery Woman," wrote: "So sad to hear about the passing of the wonderful actor #ClarenceWilliamsIII Working with him on Mystery Woman was an honor. Rest In Peace, my friend."