Plans for the chapel, designed by architect Robert Curwen, were first presented to the school's second headmaster, W. T. A. Barber; he deemed the project an unnecessary luxury.
The foundation stone was laid at the marble West Door by Princess Helena of Waldeck and Pyrmont on 8 June 1905 and the chapel was consecrated on 27 October 1906.
A memorial to the old Leysians who died, costing £48,000 and funded by donation, was on 6 June 1920 unveiled by the Duke of York, later King George VI.
The memorial consists of four rows of names divided in the middle by a statue of an armoured St George, below which is written "To The Immortal Memory of Old Leysians Who Fell In The War Of 1914–1919", and in large block capitals the words "My Marks And Scars With Me To Be A Witness For Me That I Have Fought His Battles Who Now Will Be My Reward."
The pulpit is made of oak and has a brass inscription reading "To the Glory of God and for the Preaching of His holy word this Pulpit was carved by Anne Hobson, Helen Mary Chubb, and George Hayter Chubb, and presented by the latter to The Leys, October, 1906."