Richardson High School (RHS) is a magnet high school in Richardson, Texas, United States with approximately 2,770 students and a student/teacher ratio of approximately 15:1 in the 2018–2019 school year. It is the oldest high school in the Richardson Independent School District (RISD).

Richardson is a city in Dallas and Collin counties in the U.S. state of Texas. As of the 2020 United States census, the city had a total population of 119,469. Richardson is an inner suburb of the city of Dallas.