Stewart Udall, American lawyer and politician, 37th United States Secretary of the Interior (died 2010)

Stewart Lee Udall was an American politician and later, a federal government official who belonged to the Democratic Party. After serving three terms as a congressman from Arizona, he served as Secretary of the Interior from 1961 to 1969, under presidents John F. Kennedy and Lyndon B. Johnson. A staunch liberal, he is best known for enthusiastically promoting environmentalism while in the cabinet, with success primarily under President Johnson.

The United States secretary of the interior is the head of the United States Department of the Interior. The secretary and the Department of the Interior are responsible for the management and conservation of most federal land along with natural resources, leading such agencies as the Bureau of Land Management, the United States Geological Survey, the Bureau of Indian Affairs and the National Park Service. The secretary also serves on and appoints the private citizens on the National Park Foundation Board. The secretary is a member of the United States Cabinet and reports to the president of the United States. The function of the U.S. Department of the Interior is different from that of the interior minister designated in many other countries.

January 31 is the 31st day of the year in the Gregorian calendar; 334 days remain until the end of the year.