Harold "Slim" Halderson (January 7, 1898 – August 1, 1965) was a Canadian ice hockey player who competed in the 1920 Summer Olympics. He was born in Winnipeg, Manitoba to Icelandic immigrants. Slim was the right wing for the Winnipeg Falcons, the Canadian team which won the gold medal. Slim then joined the Victoria Cougars and helped them win the Stanley Cup in 1925.