Through its subsidiary The Royal Marsden School, it offers undergraduate and postgraduate degrees in cancer care validated by the University of East Anglia.

[1] The Belmont site is in the far south of Greater London, adjacent to the former Sutton Hospital, High Down and Downview Prisons, and the Metropolitan Green Belt.

This site houses some of the hospital's large diagnostic and radiotherapy equipment, including the UK's only combined MR-Linac.

The ICR's laboratories are located alongside the Royal Marsden in Brompton and Belmont, and the two organisations produce a joint research strategy.

[7] Many of the hospital's consultants also have research roles with the ICR,[8] and some facilities are shared between the organisations, such as the Joint Department of Physics, which operates the linac.

It was founded as the Free Cancer Hospital in 1851 by William Marsden at 1, Cannon Row, Westminster.

Marsden, deeply affected by the death of his wife Elizabeth Ann from cancer, resolved to classify tumours, research the causes and find new treatments.

The hospital at first consisted solely of a dispensary and the drugs prescribed were palliative and aimed at treating symptoms, but it allowed William Marsden the opportunity to study and research the disease.

[11][12] The hospital quickly outgrew its original premises as it became apparent that some patients required inpatient care.

[11][14] In response to the need to expand to treat more patients and train more doctors, a second hospital in Sutton, London, was opened in 1962.

[18] All 200 staff, outpatients, and 79 inpatients were evacuated to a local church and the neighbouring Royal Brompton Hospital, some carried on mattresses by emergency responders and doctors.

[22][23] Professor of radiotherapy at the University of London David Waldron Smithers chaired the committee that constructed and established the Surrey branch of the Marsden, which was opened in 1963.

[24][25] The Royal Marsden's main lecture theatre is named in honour of consultant radiotherapist Julian Bloom.