Calybute Downing (1606–1644) was an English clergyman, a member of the Westminster Assembly. Also a civil lawyer, he is now remembered for political views, which moved from an absolutist position in the 1630s to a justification of resistance to authority by 1640, within a contractarian setting.
He was son of Calybute Downing of Sherrington in Gloucestershire, and Elizabeth Morrison née Wingfield who married in Dec. 1604 at Tinwell, Rutland [ref.DE2271/1 Tinwell, Rutland]. He was baptised 27 Oct. 1605 St. Andrews, at Northborough, Northamptonshire . He became a commoner of Oriel College, Oxford, in 1623, and proceeded B. A. in 1626; he then left Oxford and would seem to have been curate at Quainton, Buckinghamshire, where on 2 December 1627 he married Margaret, the daughter of Richard Brett the rector. In 1630, having entered Peterhouse, Cambridge, he proceeded M.A., and in 1637 LL. D.
In 1632 he was made rector of Ickford, Buckinghamshire, and about the same time of West Ilsley, Berkshire, and was an unsuccessful competitor against Gilbert Sheldon for the wardenship of All Souls' College, Oxford. In 1637 he resigned West Ilsley for the vicarage of Hackney, London. According to Anthony Wood, he aimed at a chaplaincy to Thomas Wentworth, and so wrote in favour of episcopacy. In 1640, preaching before the Artillery Company of London on 1 September, he stated that for defence of religion and reformation of the church it was lawful to take up arms against the king. A Letter from Mercurius Civicus to Mercurius Rusticus (1643) comments that Downing on this occasion was acting for Puritan leaders to test opinion, and that after preaching the sermon he went to the house of Robert Rich, 2nd Earl of Warwick at Little Lees, Essex. Wood adds that he became chaplain to Lord Robartes's regiment in the Earl of Essex's army.