The National Park Service (NPS) is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations. It was created on August 25, 1916, by Congress through the National Park Service Organic Act.

It is an agency of the United States Department of the Interior, a federal executive department whose head, the Secretary of the Interior, is a Cabinet officer nominated by the President and confirmed by the Senate. Most of the direct management of the NPS is delegated by the Secretary to the National Park Service Director, who must also be confirmed by the Senate.

The 21,989 employees of the NPS oversee 401 units, of which 59 are designated national parks.