An American photographer and environmentalist. His black-and-white landscape photographs of the American West, especially Yosemite National Park, have been widely reproduced.

Born in San Francisco to a wealthy family, he found joy in nature from an early age, spending substantial time every year in the Yosemite Sierra. He had his first published photographs in 1922 and his first exhibition in 1928 and began to make a living from photography. He developed the Zone System as a way to determine proper exposure and adjust the contrast and tonality of the final print. The resulting clarity and depth characterised his photographs. He primarily used large-format cameras because their high resolution helped ensure sharpness in his images.

In 1927, he met Edward Weston and they became close friends and colleagues, forming the renowned Group f/64 in 1932. He made his first visit to New York in 1933 to meet photographer Alfred Stieglitz, the artist whose work and philosophy Adams most admired and whose life of commitment to the medium he consciously emulated. In 1936, Stieglitz gave Adams a one-man show at An American Place.