Haldor Halderson (Halldór Halldórsson; January 7, 1898 – August 1, 1965) was an Icelandic-Canadian ice hockey player who competed in the 1920 Summer Olympics. Halderson was the right wing for the Winnipeg Falcons, the Canadian team which won the Olympic gold medal in 1920. Slim then joined the Victoria Aristocrats/Victoria Cougars and helped them win the Stanley Cup in 1925. On both occasions he was a teammate of fellow Icelandic-Canadian ice hockey star Frank Fredrickson, making them the first players to win an Olympic gold medal and a Stanley Cup.