Haldor Halderson (Halldór Halldórsson; January 7, 1898 – August 1, 1965)[1][2] was an Icelandic-Canadian ice hockey player who competed in the 1920 Summer Olympics.

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.

Halderson was nicknamed "Slim" due to his lanky frame during his first years in senior amateur and professional hockey.

At the start of the 1921–22 season, Halderson's first in the PCHA with the Victoria Aristocrats, he weighed in at only 166 pounds on a 6 feet 2 inches frame.

Sterling hired a detective who discovered that Halderson and teammate Robert Benson received C$6,500 to play amateur hockey.