McKinney is a city in and the county seat of Collin County, Texas, United States. It is Collin County's second-largest city, after Plano. Part of the Dallas-Fort Worth metroplex, McKinney is about 32 miles (51 km) north of Dallas.
The Census Bureau listed McKinney as the nation's fastest-growing city from 2000 to 2003 and again in 2006, among cities with more than 50,000 people. In 2007, it was ranked second-fastest-growing among cities with more than 100,000 people and in 2008 as third-fastest. In the 2010 census, the city's population was 131,117, making it Texas's 19th-most populous city. The most recent population estimate, produced by the city as of January 1, 2019, is 187,802. As of May 2017, McKinney City was the third-fastest-growing city in the United States.