St Bartholowmew the Less, stands on the site of one of the Chapels of the medieval hospital, the Chapel of the Holy Cross.
When the Priory Church of St Bartholowmew the great was dissolved in 1543 the Chapel of the Holy Cross became the parish church for the inhabitants of the site and for the patients and staff. It was to be called the Church of St Bartholomew the Less.
As the extent of the Parish was and still is the hospital, St Bartholomew's is unique among English hospitals as being a parish in its own right .
All that remains of the medieval church is the tower with two of its four bells and the west wall. The church was rebuilt in its present form between 1823 and 1825 and is a reworking of the previous re-ordering by George Dance, the Younger, builder of the Mansion House.