The Oratory School was founded in Edgbaston by Blessed Saint John Henry Newman 'for the education of (Catholic) boys not destined to the ecclesiastical estate.'
The school opened on 2 May 1859 with nine boys on roll, all of prep school age.
Perhaps because the suburbs of Birmingham were encroaching too closely, in 1922 The Oratory School moved to Caversham Park near Reading, Three years after that and less than a mile away The Oratory Preparatory School opened with just four boys at 'Rose Hill House', a Georgian-style mansion in Emmer Green. The first Headmaster was Father Sebastian Ritchie and by 1930 there were 30 boys.
In 1938 ill health forced Father Ritchie's retirement and mounting financial difficulties meant that Rose Hill had to be sold and the OPS took the top floor of Caversham Park with 15 boys and Ronald Richings as Head. By 1940 there were over 50 boys.
In 1941 Caversham Park was sold and The Oratory Preparatory School merged with Worth Preparatory School at a temporary wartime home at Downside. After only two terms The Oratory School re-established itself at Woodcote House and three cottages in Exlade Street – just opposite the front entrance – formed a school for a small number of younger boys aged 10 to 13 pending the opening of a new Prep School.
In 1946 The Oratory Preparatory School re-opened its doors to 35 boys at the 'Old Ryde', a lovely mansion at the Branksome Park end of Poole and training runs were conducted on the beach before breakfast. The Headmaster was Antony Patton. He was succeeded by Cyril Bull and then in 1958 by Christopher 'Kit' Maude.
Maude's retirement in 1968 coincided with the move from Branksome to the Prep School's current site in Crays Pond. Only two miles from The Oratory School this was the former home of the prep school to St Mary's, Wantage. The nuns had converted and extended the billiards room of the house into a chapel for their services and, re-consecrated as a Catholic Chapel in 1968, it has ever since been used for Mass as part of the regular rhythm of the school's Catholic life. 95 boys from Branksome joined with 25 from Elston Hall near Newark, bringing the numbers up to the largest there had ever been. For a time the Elston Hall boys operated as a separate house within the school, retaining their old uniform.
Patrick Stow was now the headmaster and in 1970 a Pre-Preparatory Department opened with 21 pupils, including girls for the first time. By 1977 George Robertson was headmaster and then in 1981 it was the turn of Michael Randell and under his guidance the school saw the start of major projects and building developments, which accelerated under David Sexon's headship between 1991 and 2006. The school became fully co-educational and total numbers grew to over 400 pupils. On David's retirement Richard Hillier became Headmaster. When in 2010 Richard took over the headship at the Yehudi Menuhin International Music School, Joseph Smith – ex English teacher, sports coach and housemaster at Monkton Combe School near Bath - became the eleventh headmaster of The Oratory Preparatory School.
In January 2017 Mr Rob Stewart became the twelfth Headmaster of The Oratory Preparatory School.