This list of birds of Iowa includes species documented in the U.S. state of Iowa and accepted by the Iowa Ornithologists' Union (IOU). As of August 2021, there are 431 species included in the official list. Of them, 91 are classed as accidental, 29 are classed as casual, eight have been introduced to North America, three are extinct, and one has been extirpated. The following codes are used to designate some species: