Thomas C. Clark High School is a public high school, in the Northside Independent School District, in San Antonio, Texas, United States. Built in 1978 with five main buildings surrounding a courtyard, this school has over 120 classrooms and is one of the largest schools in NISD. As with all Northside ISD schools, Clark is named for a former or current United States Supreme Court Justice, in this case Thomas C. Clark. Clark serves the NISD portion of Scenic Oaks.