Southlake is a city in northeastern Tarrant an southern Denton Counties in the U.S. state of Texas. It is a suburb in the Dallas/Fort Worth Metroplex and is located near the cities of Grapevine, Colleyville, and Keller. The population was 21,519 at the 2000 census. Southlake is well known for its Southlake Town Square project, a shopping center located on State Highway 114 and Southlake Boulevard. A plan was approved in March 2005 that allowed the Town Square's area to be doubled.