Ruedi Keller represented the Grasshopper Club in Zürich from 1942 until 1956 where he played both field and ice hockey. Keller competed in the former discipline at the 1952 Oslo Olympics where Switzerland was eliminated in the semi-finals of the consolation round after losing to Poland. He was much more at home on the ice, making his international début at the 1953 World Championships. During the tournament he fractured his wrist, forcing him to miss most of the matches, but Switzerland won bronze after Czechoslovakia withdrew from the competition. Three years later Keller played in one match at the 1956 Cortina d’Ampezzo Olympics. He later became part of the Swiss Ice Hockey Federation but resigned in 1972 due to disagreements with other members of the organisation.