Ernst Hilding Waldemar Nilsson (10 May 1891 – 11 February 1971) was a Swedish heavyweight wrestler who competed at the 1912, 1920 and 1924 Summer Olympics.
He won a bronze medal in freestyle wrestling in 1920 and placed fourth-fifth in the Greco-Roman and freestyle contests in 1924.
Nilsson won two world titles in Greco-Roman wrestling, in 1913 and 1922.