Charles Gald Sibley (August 7, 1917 – April 12, 1998) was an American ornithologist and molecular biologist. He had an immense influence on the scientific classification of birds, and the work that Sibley initiated has substantially altered our understanding of the evolutionary history of modern birds.
Sibley's taxonomy has been a major influence on the sequences adopted by ornithological organizations, especially the American Ornithologists' Union.
Charles Sibley is of no known family relation to renowned bird artist and prolific author of numerous bird identification guides David Sibley.