Conroe High School opened in 1964, replacing Davy Crockett High School as the District's flagship campus, and served all of the current footprint of CISD until McCullough High School opened in 1976. The main Conroe High campus is located on Highway 105 and Longmire Road, while the 9th Grade Campus opened in 2013 and is located on Sgt. Ed Holcomb Blvd.

To accommodate the growth in becoming the second-largest high school by student population in the State of Texas, the main campus has been undergoing a transformation since 2018. The final phase of construction is expected to be completed for the start of the 2026-2027 school year and will see the front of the building shift from facing Highway 105 to facing Longmire Road.