Chautauqua County is a county located in the U.S. state of New York. As of the 2010 census, the population was 134,905. Its name may be a contraction of a Seneca Indian word meaning "bag tied in the middle". Its county seat is Mayville, and its largest city is Jamestown.
Chautauqua County was created by the partition of Genesee County on March 11, 1808. This partition was performed under the same terms that produced Cattaraugus and Niagara Counties. The partition was performed for political purposes, but the counties were not properly organized, so they were all controlled as part of Niagara County.
On February 9, 1811, Chautauqua was completely organized, and so its separate government was launched. This established Chautauqua as a county of 1,100 square miles (2,848.99 square km) of land. Chautauqua was never altered.