Under George Rattray, in 1907 the school was named Selborne College in honour of the Second Earl of Selborn (William Waldegrave Palmer), High Commissioner from 1905 to 1910, whose Selborne Memorandum became the blueprint for the Union of South Africa.
The Selborne family coat of arms and motto were adopted as the College badge and motto. Palma Virtuti ('Reward is to the Brave') underpins the approach to both the academic and extra-curricular activities of the school. By 1920 it became evident that the school was once again outgrowing its premises and in May 1922 the foundation stone was laid by Sir Frederick de Waal, Administrator of the Cape, on the present site of Selborne College.
