 The school motto is "Flagrans Veritatis Studio" ("Burning with the Zeal for Truth").Glenmuir opened its doors on September 15, 1958 with 55 students but it was not until September 30 that Sir Kenneth Blackburne, Governor of Jamaica, performed the official opening ceremony.The main administrative building (which included the library, classrooms, the Headmaster's office, and a flat on the first floor for his family) was originally the home of the Custos of Clarendon, George W. Muirhead, C.M.G.