Westwood High School (abbreviated WHS) is a public, four-year secondary school in the Anderson Mill neighborhood, Austin, Texas, and is part of the Round Rock Independent School District.  It opened in 1981 on 12400 Mellow Meadow.

In 2018, Westwood was ranked top 100 best high schools in Texas by Newsweek. 

Westwood offers honors and Advanced Placement courses to all students and further houses a district level International Baccalaureate magnet program. This combination of honors, AP and IB courses supports not only a robust college matriculation rate but also imparts a college preparatory element to upper division courses. In 2013, Westwood produced 50 National Merit Semifinalists, one of the highest numbers in the nation. Westwood has also produced USAMO qualifiers as well as physics and chemistry olympiad semifinalists.

Westwood offers 25 AP classes.  Several IB classes at Westwood are coordinated with AP classes in the form of AP/IB classrooms, providing students with the benefits of both programs.  Westwood is also home to a school district wide International Baccalaureate diploma program which operates under its own admissions process.  Westwood's Academy Program allows students to explore interests in different fields. It is divided into five areas of study: Science, Technology, Engineering, and Math (STEM); Business and Industry; Visual and Performing Arts; Health Sciences; and Public Service.

The athletics department at Westwood has dominated many sports in the past, winning multiple district, bi-district, area and so on championships including many state championships in Volleyball, Tennis, Golf, Soccer and Swimming.  The Westwood Warrior football team has won a handful of district championships, most recently when the 2006 Warriors qualified as area finalists.  The Warrior basketball team has also had success throughout the years, obtaining a winning record since the team began in 1981. The Warriors baseball team has made the state playoffs almost every year in the team's existence. The Warriors Swimming and Diving Team continues to dominate the district and consistently produce state champions. Between 1999 and 2008 Warriors Swimming and Diving dominated 9 consecutive district meets and had multiple perfect regular season records. Between 2010 and 2018 The Westwood Tennis team dominated 8 consecutive district titles and had multiple perfect regular season records.