Collin County is a suburban county located in Texas. The county has been experiencing explosive growth in recent years. In 2000, its population was 491,675; in 2007 the U.S. Census Bureau estimated that its population had reached 730,690. The county and its seat (McKinney) are both named in honor of Collin McKinney, one of the five men who drafted the Texas Declaration of Independence and the oldest of the 59 men who signed it.
Collin County is part of the Dallas/Fort Worth Metroplex. A small portion of the city of Dallas is located in the county. Other important cities in the county include Allen, Frisco, McKinney, Plano, Richardson, and Wylie. Collin County is the richest county in Texas and the 23rd wealthiest county in the country.