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, 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.

The United States Department of the Interior (DOI) is an executive department of the U.S. federal government responsible for the management and conservation of most federal lands and natural resources. It also administers programs relating to Native Americans, Alaska Natives, Native Hawaiians, territorial affairs, and insular areas of the United States, as well as programs related to historic preservation. About 75% of federal public land is managed by the department, with most of the remainder managed by the Department of Agriculture's Forest Service. The department was created on March 3, 1849. It is headquartered at the Main Interior Building, located at 1849 C Street NW in Washington, D.C.