Yosemite National Park (/joʊˈsɛmɪti/ yoh-SEM-i-tee)is an American national park located in the western Sierra Nevada of Central California, bounded on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers an area of 747,956 acres (1,168.681 sq mi; 302,687 ha; 3,026.87 km2) and sits in four counties: centered in Tuolumne and Mariposa, extending north and east to Mono and south to Madera County. Designated a World Heritage site in 1984, Yosemite is internationally recognized for its granite cliffs, waterfalls, clear streams, giant sequoia groves, lakes, mountains, meadows, glaciers, and biological diversity. Almost 95% of the park is designated wilderness.

On average, about 4 million people visit Yosemite each year, and most spend the majority of their time in the 5.9 square miles (15 km2) of Yosemite Valley. The park set a visitation record in 2016, surpassing 5 million visitors for the first time in its history. Yosemite was central to the development of the national park idea. Galen Clark and others lobbied to protect Yosemite Valley from development, ultimately leading to President Abraham Lincoln’s signing the Yosemite Grant in 1864. John Muir led a successful movement to have Congress establish a larger national park by 1890, one which encompassed the valley and its surrounding mountains and forests, paving the way for the National Park System.