Cattaraugus County is a county in Western New York, with one side bordering Pennsylvania. As of the United States 2020 census, the population was 77,042. The county seat is Little Valley. The county was created in 1808 and later organized in 1817. The county is part of the Western New York region of the state.

Western New York (WNY) is the westernmost region of the U.S. state of New York. The eastern boundary of the region is not consistently defined by state agencies or those who call themselves "Western New Yorkers". Almost all sources agree WNY includes the cities of Buffalo, Niagara Falls, Jamestown, and the surrounding suburbs, as well as the outlying rural areas of the Great Lakes lowlands and Niagara Frontier, and Chautauqua-Alleghany. Many would also place Rochester and the Genesee Valley in the region, while some would also include the western Finger Lakes within the region. Others would describe the latter three areas as being in a separate Finger Lakes region.