Clifford Williams (born 14 December 1949) is an English retired musician and singer, best known as the bassist and backing vocalist of the Australian hard rock band AC/DC from 1977 until his retirement in 2016. He started his professional music career in 1967 and had previously been in the English groups Home and Bandit. His first studio album with AC/DC was Powerage in 1978. Williams was inducted into the American Rock and Roll Hall of Fame as a member of AC/DC in 2003. His side projects include benefit concerts.