McKinney is a city in and the county seat of Collin County, Texas, United States, and the second in population to Plano. According to the U.S. Census Bureau, the city's 2010 population was 131,117 making it the nineteenth most populous city in the state of Texas. It is part of the Dallas-Fort Worth metroplex, and is located about 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. The most recent population estimate, as of January 1, 2015, is 155,142.