Geezer Butler (born Terence Michael Joseph Butler on 17 July 1949 in Birmingham, England) is the English musician and songwriter. Butler is best known as the bassist and lyricist of heavy metal band Black Sabbath. He is also currently involved in Heaven and Hell.
Butler formed his first band, Rare Breed, with old friend John "Ozzy" Osbourne in the autumn of 1967. Separated for a time, Osbourne and Butler reunited in the blues foursome, Polka Tulk, along with guitarist Tony Iommi and drummer Bill Ward. They renamed their band Earth, but after finding a band in the small-time English circuit with the same name, soon adopted Black Sabbath in early 1969.
Butler played rhythm guitar in his pre-Sabbath days, including with Rare Breed, but when Sabbath was formed, Iommi made it clear that he wouldn't want to play with another guitarist, so Butler moved to bass.