Claude Berkeley Williamson (November 18, 1926 – July 16, 2016) was an American jazz pianist.

Williamson was born in Brattleboro, Vermont, United States. He studied at the New England Conservatory of Music before moving to jazz, influenced mainly by Teddy Wilson, then by Al Haig and Bud Powell. In 1947, he moved to California, working first with Teddy Edwards, then with Red Norvo in San Francisco, with Charlie Barnet in 1949, and with June Christy for two years. Later he worked with Max Roach, Art Pepper and others. Williamson was a longtime member of the Lighthouse All-Stars (substituting for pianist Russ Freeman), performing with Bud Shank, Stan Levey, Bob Cooper, Conte Candoli and Howard Rumsey. In 1956, he became the piano player in the Bud Shank quartet. In 1968, he started working as a pianist for NBC, first on The Andy Williams Show, then for Sonny and Cher. In 1978, Williamson went back to the jazz world and released many albums, mainly for Japanese labels, often accompanied by Sam Jones and Roy Haynes. In 1995 he made a trio recording for Fresh Sound Records at the Jazz Bakery in Los Angeles.

His younger brother was trumpeter Stu Williamson (1933–1991).

He died on July 16, 2016, at the age of 89.