- Your Ad Here County of Erie, commonly referred to as Erie County, is a county located in the U.S. state of New York. As of the 2016 census, the population was 921,046. The county seat is Buffalo. Sponsored Links History Erie County was established in 1821. The county's name comes from Lake Erie, which in turn comes from the Erie tribe of Indians who lived south and east of the lake before 1654. |