Collin County, Texas

Collin County
The Collin County Courthouse in McKinney
Location within the U.S. state of Texas
Texas's location within the U.S.
Coordinates: 33°11′N 96°35′W / 33.18°N 96.58°W / 33.18; -96.58
Country United States
State Texas
Founded1846
Named afterCollin McKinney
SeatMcKinney
Largest cityPlano
Area
  Total
886 sq mi (2,290 km2)
  Land841 sq mi (2,180 km2)
  Water45 sq mi (120 km2)  5.1%
Population
 (2020)
  Total
1,064,465
  Estimate 
(2024)
1,254,658
  Density1,200/sq mi (460/km2)
Time zoneUTC−6 (Central)
  Summer (DST)UTC−5 (CDT)
Congressional districts3rd, 4th, 32nd
Websitewww.collincountytx.gov

Collin County is a county in the northern part of the U.S. state of Texas. It is part of the Dallas-Fort Worth-Arlington metropolitan statistical area, and a small portion of the city of Dallas is in the county. At the 2020 United States census, the county's population was 1,064,465, making it Texas's sixth-most populous county and the 43rd-largest county by population in the United States. Its county seat is McKinney.