William J. Brennan High School is the tenth public high school in the Northside Independent School District of San Antonio, Texas, United States. It is a four-year high school that opened in 2010 and graduated its first senior class in June 2012. In 2017, the school was rated "Met Standard" by the Texas Education Agency, with a 2-Star Distinction for Academic Achievements in Top 25 Percent Student Progress and Postsecondary Readiness.