Helmer Julius Hanssen (* September 24 1870 in Bjørnskinn, now part of the commune Andøy; † August 2, 1956 in Tromsø) was a Norwegian polar explorer. He accompanied Roald Amundsen on several expeditions.
Helmer Hanssen grew up on his father's farm on in Bjørnskinn. Up to the age of 24 he helped his father in agriculture and worked in seasonal fishing. In 1894 he hired on a whaler, who hunted in the waters between Jan Mayen and Svalbard on minke and beluga whales. In 1896, he worked as sealers. In March 1897, he put in Kristiansund from his helmsman exam. Then he went on board the Laura after Novaya Zemlya. In the same year Hanssen married and settled with his wife in Tromso. He found a job with the Vester Aalen Dampskibsselskab and sailed the Norwegian coast waters and the Arctic Ocean. In the summer of 1898 he chartered the ELLIDA for the seal hunt in Spitsbergen and led for the first time in command of a ship. In 1901 he left his previous employer and hired on the Leander, with which he went to England, the Black Sea and Hamburg.
1903 and 1906 took Helmer Hanssen, who was now an experienced Eislotse, as second officer on Roald Amundsen's successful journey through the Northwest Passage aboard the Gjoa part. During the nearly two-year stay of the expedition in a natural harbor on the southeast coast of King William Island he learned from the Inuit how to run sled dogs.
In 1910 he set out with Amundsen to reach the South Pole, this time he went as an experienced dog handlers with. He was also responsible for navigation and led the Leitkompass on his sleigh with it. On December 14, 1911, he reached together with Roald Amundsen, Olav Bjaaland, Oscar Sverre Hassel Wisting and the first man to the South Pole. It is likely that Hanssen during the stay at the South Pole the mathematical point at about 200 meters actually happened very accurate for the navigational possibilities of the expedition.