William Dutcher (20 January 1846 - 1 July 1920) was an American businessman, amateur bird photographer, ornithologist and a keen proponent of bird conservation. Working in a New York insurance company, he provided support to the American Ornithologists' Union (AOU) in its early years by serving as its treasurer and by working with government agencies to help pass key legislations for the protection of birds and the establishment of bird reserves.