Lincoln Ellsworth (1880-1951), American explorer and engineer, and a leader of transarctic and transantarctic flights. He was born in Chicago on May 12, 1880.

Ellsworth organized and led (1924) a geological survey of the Andes Mountains from the Pacific Ocean to the headwaters of the Amazon River. He became an associate and financial supporter of the Norwegian explorer Roald Amundsen, and in May 1925 they and four companions attempted to fly over the North Pole. They took off from Svalbard in two amphibious airplanes but were forced to land just short of the pole. The following year, with the Italian explorer and engineer Umberto Nobile, Ellsworth and Amundsen carried out a 5460-km (3390-mi) flight in the dirigible Norge, from Kongsfjord, Svalbard, across the North Pole to Teller, Alaska. In November 1935 Ellsworth made the first airplane flight across the Antarctic from the Weddell Sea to the Ross Sea. He collaborated with Amundsen in writing Our Polar Flight (1925) and First Crossing of the Polar Sea (1927). Ellsworth also wrote Search (1932) and Beyond Horizons (1938). He died in New York City on May 26, 1951.