Swedish athlete who was the only person to win two individual Olympic gold medals in the modern pentathlon. A carpenter from Göteborg, he was the first nonmilitary winner of the individual modern pentathlon.

Hall was the world champion in the pentathlon in 1950 and 1951 and was a favourite at the 1952 Olympic Games in Helsinki. He won the gold, but not without some luck: in the riding event Hall's horse came up lame, and the replacement horse turned out to be the best mount in the competition. Hall then arrived late for the pistol competition but was spared disqualification owing to a protest from the Soviet team that had delayed the event. Hall's exceptional swimming and running then clinched the gold medal. At the 1956 Olympics in Melbourne, Hall's swimming and running helped him to overcome a poor shooting performance, and he won his second consecutive individual gold medal.