San Marcos Treatment Center is a psychiatric residential treatment facility for children and adolescents in San Marcos, Texas. Its public materials state that the center was founded in 1940 and provides intensive psychiatric residential evaluation and treatment for children and adolescents from the United States and abroad (San Marcos Treatment Center, San Marcos Treatment Center about).

The center describes residential treatment programs for children ages 6 to 13 and adolescent programming for older youth, with treatment for psychiatric, behavioral, developmental, trauma-related, and substance-use concerns. The San Marcos Area Chamber of Commerce describes the facility as serving children and adolescents ages 6 to 17 (Child programs, San Marcos Chamber).