Clerkenwell Board of Guardians was the body responsible for administering the poor law in the parish of St James and St John, Clerkenwell from 1775-1869.
The board was formed by private act of parliament and was not affected by the Poor Law reforms of 1834. In 1869 the parish became part of the Holborn Poor Law Union.
For more information see peter Higginbotham's website https://www.workhouses.org.uk/Clerkenwell/.