The Phoenix Union High School District is a high school-only school district in Phoenix, Arizona, United States. It is one of five high school-only districts in the Phoenix area.

Phoenix Union High School (PUHS) was a high school that was part of the Phoenix Union High School District in downtown Phoenix, Arizona, one of five high school-only school districts in the Phoenix area. Founded in 1895 and closed in 1992, the school consisted of numerous buildings on a campus which by 1928 consisted of 18 acres.