McKinney is a city and the county seat of Collin County, Texas, United States. It is Collin County's third-largest city, after Plano and Frisco. A suburb of the Dallas–Fort Worth metroplex, McKinney is about 32 miles north of Dallas. The Census Bureau ranked McKinney as the nation's fourth fastest-growing large city from 2010 to 2019 and determined the city's 2020 population was 195,308.