He won an Olympic gold medal for the first time in the Stockholm 1912 Olympic Games. At the 1920 Antwerp Olympics he won his second 100-meter freestyle and another gold medal in the 4x200m relay (where he was teammates with Norman Ross). "The Duke", as he was commonly known, also won two silver medals in 1912 and at the 1924 Paris Olympics.
As a passionate surfer, between his Olympic Games, The Duke traveled the world for swimming exhibitions where he presented and promoted surfing around the world. For that, Kahanamoku became also known by his nickname, the "Father of Surfing".