St Catherine's opened its doors to 11 boarders and 6 day students in September 1885 under Miss Susan Burnett, the first Headmistress who shortly afterwards left, and the first long-standing Headmistress, Mrs Charlotte Russell-Baker, took the helm and became a redoubtable figure in the history of the School.

Another landmark was reached in 1894 with the completion and dedication of the beautiful Chapel building with its Kempe stained glass and Father Willis organ. Shortly after that work began on another wing of the main building. Thus it was that St Catherine's became one of the significant number of girls' schools to be founded in the late nineteenth century by imaginative and dedicated men and women, a tradition which has served the girls of this country extraordinarily well and continues so to do. The School's history over its first century is one of steady development in every area. Numbers today are 720 and embrace a Preparatory School sorority of 200. The mix continues to be one of day girls and boarders and the boarding provision plays a crucial part in establishing the homely and welcoming atmosphere of which the School is fiercely proud. 

Decades of expansion, new buildings and the Centenary celebrations followed, and now the latest chapter in the history of St Catherine’s has been completed with the construction of the Millennium wall of tiles. Every girl, and almost everyone else involved in the life of the school, from Governors and teachers to the Headmistress and the kitchen staff, decorated a tile which was then glazed and fired. The Head of Art, Jane Silk, then had the huge task of arranging them on the wall by the entrance to Main School. A unique and fascinating memorial to the new Millennium now exists to complement the new and refurbished buildings. In the words of the school motto ‘Let us go on.............