Nansen, Fridtiof (1861–1930), a Norwegian Arctic explorer, scientist, and statesman. Nansen was the first to cross Greenland and came closer to the North Pole than any previous explorer. After World War I he helped resettle prisoners of war and refugees and organized the transport of food supplies to millions of starving Russians. For these contributions Nansen received the 1922 Nobel Peace Prize.

Nansen was born near Christiania (now Oslo). At the University of Christiania he specialized in zoology. In 1882 he made his first voyage into the Arctic Ocean, to study seals and other animals. On his return Nansen became curator of the zoological collection at a Bergen museum. He continued his studies and received his doctorate in 1888.

In 1888 Nansen led the first expedition across Greenland, traveling on skis from the east to the west coast. Nansen then became curator of zoology at a museum of the University of Christiania, later (1897) becoming a professor at the university.

Nansen's expedition of 1893–96 explored new arctic regions. With the Fram ("forward"), a ship designed to withstand the crush of polar ice, Nansen hoped to be the first to reach the North Pole. After reaching latitude 83º59, he and a companion left the ship and pushed northward by dog-sled and kayak as far as latitude 86º14. This was almost 200 miles (320 km) nearer the pole than any explorer had come before, but 226 miles (364 km) short of the goal. Nansen, however, had virtually proved that there is no land near the pole, only a continually shifting expanse of polar ice.

During the Fram expedition, Nansen devised a special container for taking samples of seawater, which came to be called the Nansen bottle.

Nansen made a number of other research voyages, but after World War I broke out in 1914, he turned to humanitarian work. As the League of Nations' High Commissioner of Refugees in 1921, he repatriated almost 500,000 prisoners of war and helped resettle large numbers of Armenian and anti-Bolshevik Russian refugees. As commissioner of the International Red Cross, 1921–23, Nansen directed its drive to feed millions during a famine in Russia, He led Norway's delegation to the League of Nations from 1920 until his death. The League's bureau for dealing with refugees was named the Nansen International Office for Refugees in his honor.

Among Nansen's books are Across Greenland (1891); Farthest North (1897); and Armenia and the Far East (1928).