This list of birds of Ontario includes all the bird species recorded in the Canadian province of Ontario as determined by the Ontario Bird Records Committee (OBRC). As of August 2024 there were 511 species on this list, 291 of which are known to breed in the province. Ontario has a considerable variety of bird species. One of the factors in this diversity is the size and range of environments in Ontario. Another is the Great Lakes; many birds use the shores as a stopping point during migration.