Mark Klett (born 1952) is an American photographer.
Klett was born in Albany, New York. After graduating from St. Lawrence University with a B.S. in Geology in 1974, he worked as a photographer with the U.S. Geological Survey. In 1977, he completed an MFA from the Visual Studies Workshop in Rochester, New York studying with Nathan Lyons. Klett's photographic work focuses on explorations of man’s interaction with the American landscape, and more recently on issues of photography in time including rephotography. He is a Regents Professor and teaches photography at Arizona State University, and lives with his wife and two daughters in Tempe, Arizona.