Willem "Wim" Ruska (born 29 August 1940) is a retired judoka from the Netherlands. He is the only athlete to win two judo medals in one Olympics – in the heavyweight and absolute categories in 1972.
He started mastering in Judo in 1960 and traveled to Japan for training. In the 1960s and 1970s he won seven European titles, five in the +93 kg category (1966–67, 1969, 1971–72) and two in the open category (1969 and 1972). He furthermore won two world titles (1967 and 1971) and two Olympic titles. His success at the 1972 Summer Olympics was overshadowed by the Munich massacre that took place days before.
He retired after the 1972 Olympics and later took part in a number of style-vs.-style fights. In August 1976, he defeated Ivan Gomez in a vale tudo match in Brazil. He also faced pro wrestler Antonio Inoki on three occasions. However, his matches against Inoki are believed to have had a pre-determined outcome.