Peoria High School is a public secondary school located in Peoria, Arizona, United States, serving grades 9 to 12. It is the oldest high school in the Peoria Unified School District and opened in 1919; its original building Old Main was constructed in 1922, renovated in 2014, and named a Historic Place in 2019. The school enrolls around 1,500 students, 10% of which participate in the school's Advanced Placement program. There are over 40 clubs on campus, as well as a strong athletics program.