Klaus Bonsack (born 26 December 1941), also known as Klaus-Michael Bonsack, is an East German former luger who competed during the 1960s and early 1970s.
He was born in Waltershausen, Thuringia.
He won four Winter Olympic medal in men's luge with one gold (doubles: 1968), one silver (singles: 1964), and two bronzes (singles: 1968, doubles: 1972).
Bonsack also won five medals at the FIL World Luge Championships with one gold (doubles: 1967), two silvers (doubles: 1965, singles: 1967), and two bronzes (singles: 1963, doubles: 1969).
Bonsack later served as chairman of the track construction commission, approving the final homologation of Cesana Pariol prior to the 2006 Winter Olympics for luge to compete at the track. He was among the first three inductees in the International Luge Federation (FIL) Hall of Fame in 2004, along with Paul Hildgartner and Margit Schumann.