Burley is a city in Cassia and Minidoka counties in southern Idaho, United States. The population was 11,704 at the 2020 census, up from 10,345 in 2010. The city is the county seat of Cassia County. Burley is the principal city of the Burley, Idaho, Micropolitan Statistical Area, which comprises Cassia and Minidoka counties. Burley is the largest city in Cassia and Minidoka counties, and the third-largest city in Idaho's Magic Valley region after Twin Falls, and Jerome.