St John Clerkenwell is a former parish church in Clerkenwell, London, and now the priory church of the British Crown Order of St John.

Originally part of the medieval St John's Priory, in 1931 it ceased to be a parish church and was merged with the neighbouring parish of St James', Clerkenwell.

A modest rectangular, light-brick rebuild of the former Clerkenwell Priory, it now serves as the chapel of the Order where the banners of Knights and Dames Grand Cross of St John are displayed and its investitures are held.

A chapel, crypt, garden of remembrance, and narrow Georgian entrance building alongside are owned by the Order's eventual successor (established in 1888 by Queen Victoria), the Most Venerable Order of St John which supports St John Ambulance.

A small public garden is a block south-west, beyond the Order's museum and other small retail outlets and professional offices. This replaced the Victorian enlarged version of the church.

The crumbling structure was purchased and conserved by early 18th century London's partly successful commission for Building Fifty New Churches.

St John's Church was lightly restored and improved by William Pettit Griffith in 1845. One of the large painted windows at the east end was surviving by 1878, as were remains of Grand Prior Sir Thomas Docwra's pre-Reformation church in the south and east walls, and capitals and rib mouldings underpinning the pews.

In 1868 its living, held by the Revd William Dawson, was a rectory valued £260, in the patronage of the Lord Chancellor.

In 1931, because of falling attendances, the parish was united with that of St James', Clerkenwell, when St John's ceased to be a parish church, being reconsecrated by the Crown as the Chapel of the Order of St John.

St James', the larger, successor Victorian church one block away, 150 metres to the south-west, was likewise largely gutted by bombing during The Blitz in 1941.

The Order of St John's replacement chapel was constructed from 1951 to 1958 by the architects John Seely and Paul Paget, with the crypt of the medieval building surviving in the present structure.

The outline of the round church consecrated in 1185 is marked out in St John's Square in front of St John's Clerkenwell; to the south of the church is the Garden of Remembrance that occupies the site of a 16th-century chapel.

• St John Street, London

• King, C. R. B. (1898). "The Crypt of the Priory Church of St. John, at Clerkenwell". Transactions of the Bristol and Gloucestershire Archaeological Society. 21: 168–174.
• Temple, Philip, ed. (2008). "St John's Church and St John's Square". South and East Clerkenwell. Survey of London. Vol. 46. New Haven, London: English Heritage. pp. 115–41. ISBN 9780300137279.

• GENUKI
• History of Islington - has several pages on the church and priory
• [1] - 'Archives in London' has more detail

51°31′23″N 0°6′11″W / 51.52306°N 0.10306°W / 51.52306; -0.10306