Warren Harding (June 18, 1924 – February 27, 2002) was one of the most accomplished and influential American rock climbers of the 1950s to 1970s. He was the leader of the first team to climb El Capitan, Yosemite Valley, in 1958. The route they climbed, known as The Nose, ascends 2,900 feet (880 m) up the central buttress of what is one of the largest granite monoliths in the world. Harding climbed many other first ascents in Yosemite, some 28 in all, as well as making the first true big-wall ascents in the Sierra Nevada range of California.

He was nicknamed "Batso", a reference to his penchant for spending days living on vertical cliffs and his exuberant and iconoclastic character. Harding developed specialized equipment for climbing big walls, such as the "bat tent" for sleeping, and "bat hooks" used to hook precariously on small cut-out bits of granite—examples of his B.A.T. or 'Basically Absurd Technology' products.

Harding authored the book Downward Bound: A Mad! Guide to Rock Climbing. The book contains a description of the ascent of the Nose and the Wall of Early Morning Light (1970), as well as instruction in climbing basics, ratings of prominent climbers of the period, a humorous account of rock climbing controversies and life-styles of the 1960s and 1970s.