Sidrach Simpson (c.1600-1655) was an English Independent minister, one of the leaders of the Independent faction in the Westminster Assembly.

Sidrach Simpson came from Lincolnshire. He was educated as a sizar at Emmanuel College and Queens' College, Cambridge.^[1]

After losing his Church of England status under William Laud, he spent time as a minister in the Netherlands. In the Westminster Assembly he was one of the "Five Dissenting Brethren" putting their names to the An Apologeticall Narration presented to Parliament on 3 January 1644. The others in the group were William Bridge, Jeremiah Burroughs, Thomas Goodwin and Philip Nye, all with a comparable Dutch background as ministers (Burroughs and Simpson both in Rotterdam^[2]), and united in a form of Congregationalism^[3][4] He was also in the group of ten, dominated by Independents, condemning in 1652 the Racovian Catechism, with Nye and Bridge, six further Independents,^[5] John Dury, and Adoniram Byfield.^[6]

He became Master of Pembroke Hall, Cambridge in 1650, but was drifting in his last years to the outer extremes in his positions.^{[citation needed]} He was preoccupied with his concurrent post as rector in London, at St Mary Abchurch, and then from 1653 at St Bartholomew-by-the-Exchange.^[7][8] Oliver Cromwell had him imprisoned for aggressive preaching.^[8]