This list of birds of South Dakota includes species documented in the U.S. state of South Dakota and accepted by the South Dakota Ornithologists' Union (SDOU). As of October 2021, 440 species were included in the official list. with some additions from Avibase. Of them, 67 are classed as accidental, 21 are classed as casual, four are hypothetical (see below), and eight have been introduced to North America.