Church Building Commission purchased the land in King Square from the St Bartholomew's Hospital in 1822 for the construction of a new church fronting a newly built garden square of middle-class villas.

In its original layout and with galleries on three sides the church had space for 1600 worshipers; it was consecrated as St Barnabas, King Square on 12 June 1826.

[3] In 1940 the church and nearby housing in the parish suffered damage from German bombing in the London Blitz.

The sanctuary and nave are framed by giant Corinthian columns and pilasters and there is a neo-classical plaster ceiling.

[4] The building is Grade II listed and is the only survival of the King Square of 1822.