McKinney is a city in Collin County, Texas, the county seat and second in population to Plano. As of the 2006 census, the city had a population of 102,853. The US Census Bureau listed McKinney as the nation's fastest growing city from 2000 to 2003 among cities with more than 50,000 people. This growth is due to McKinney being located at the northeastern edge of the rapid suburban development north of Dallas. Both the city and county were named after Collin McKinney, a signer of the Texas Declaration of Independence, and a congressman for the Red River district of the Republic of Texas. Mckinney apartments for rent comparison page shows most up to date rent information on Mckinney apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.