The Chapel of St. Mary and St. George was built during the headmastership of Canon Percy Umphreyville Henn, who sought funds for its construction immediately after his appointment in 1909.

He found a generous benefactor in Englishman Cecil Oliverson who paid for the full cost of the building.

During the second World War Guildford Grammar School was commandeered by the United States Navy for use as a hospital.

During the school's academic year the chapel is in daily use for services and congregational singing practices for the students.

Marriages are celebrated almost every week while Baptisms, Introductions to Holy Communion and Confirmations are held fairly frequently.