Killeen is a city in Bell County, Texas, United States. The population was 112,434 at the 2000 census. It is a "principal city" of the Killeen “Temple" Fort Hood Metropolitan Statistical Area.

Killeen is directly adjacent to the main cantonment of Fort Hood, and as such its economy is heavily dependent on the post and the soldiers (and their families) stationed there.

Killeen, Burnet and Lampasas counties are represented in the Texas House of Representatives by the semiretired veterinarian and rancher Jimmie Don Aycock, a Republican first elected on November 7, 2006.