Guildford Grammar School, informally known as Guildford Grammar, Guildford or GGS, is an independent Anglican coeducational primary and secondary day and boarding school, located in Guildford, a suburb of Perth, Western Australia. Initially established as a Single-sex school for boys only, prior to 2019, the School was co-educational from Year K to Year 6, and in Years 7, 8 and 11 in the Senior School; and in Years 9-10 and 12, the School catered for boys only. Since 2019 the School has been fully co-educational. Boarding facilities for Senior School girls were introduced from 2020.