Sir John Comyns SL (c. 1667 – 1 November 1740), of Writtle in Essex, was an English judge and Member of Parliament. He was educated at Felsted and Queens' College, Cambridge.
Comyns was a member of Lincoln's Inn, and was called to the bar in 1690. He entered Parliament in 1701 as member for Maldon, and represented that borough for 17 of the next 26 years. On three separate occasions on which he was returned for Maldon his opponents petitioned against his election, alleging bribery or improper conduct by the bailiff (who was the returning officer for the borough); but their only success was in 1715 when they also accused him of having refused to take the Qualification Oath, and his election in that case was declared void on those grounds.
He was made serjeant-at-law in 1705, and was appointed a Baron of the Exchequer and knighted in 1726, a Justice of Common Pleas in 1736 and Chief Baron of the Exchequer in 1738.
Comyns is the author of 'Reports of Cases adjudged in the Courts of King's Bench, Common Pleas, and Exchequer.' This work was written in law French. The 'Reports' were translated by the judge's nephew J. Comyns of the Inner Temple, and published in one volume in 1744, with the sanction and approbation of the judges. They were re-edited in 1792 by Samuel Rose. He is also the author of 'A Digest of the Laws of England' This work was also written in law French but afterwards translated.