St Dominic’s came into existence initially as a Convent School for Girls on the Mount Estate in Harrow-on the-Hill in the 19^th century.  The school was established in 1878.  The Dominican Nuns led by Mother Catherine Philip Bathurst OP were carrying out a direct request by Cardinal Manning, the Archbishop of Westminster, to have a Catholic Girls School in Harrow.  The Dominican nuns were committed to creating the opportunity for girls to have a good education and access to higher education. 

In the 20^th century, this Independent Girls Grammar School thrived, developed and underwent a major expansion in 1926 with the inauguration of the Old School Building – now the Catherine Building. 

When the London Borough of Harrow reorganised its education system creating a specific Sixth Form sector, the Dominican Nuns agreed to transfer the school grounds to the Diocese of Westminster as the site of the new Catholic Sixth Form College.  With the addition of a new block, the Hume Building, St Dominic’s Sixth Form College opened its doors to its first 289 students, boys and girls, in September 1979, taking its intake from the Convent School itself, the Salvatorian College (boys) and the Sacred Heart Grammar School (girls).

Up until 1993 the College was part of the Harrow Local Authority maintained system, but following the Post-16 reorganisation by the government, the College became an independent college within the State Tertiary system, the Further Education Funding Council.

This change brought about new challenges and pressures on the College, primarily to increase student numbers and its educational provision in order to cater for the educational needs in the local area.  Thus between 1997 and 2004, the College embarked on a series of expansions of the then current buildings.  In addition, after many Planning Authority delays, in July 2006 a completely new construction, the Aquinas building was inaugurated by Cardinal Cormac Murphy O’Connor.

The 21^st century marked a series of successes for the College as its reputation for delivering high quality Sixth Form education continued to spread.  By 2007 the College was among the elite group of Colleges awarded Beacon Status.

The College achieved a long-held dream of having its own indoor sports facilities. The new Gymnasium Complex, the Siena Building, was inaugurated by Cardinal Vincent Nichols in 2010.

The College is the holder of a number of national awards.  With the establishment of formal National inspection systems, St Dominic’s rose to the challenge achieving outstanding status by the Roman Catholic Diocese of Westminster for the delivery of Catholic Education.   The 2008 OFSTED Inspection too judged it to be Outstanding, a distinction it has held on to ever since.  Indeed the College is now at the very top of the league of Sixth Form Colleges for ‘Excellence’ in its educational provision and for its A level results.