Barnewall, Christopher (a. 1400–1446), lawyer and administrator, was son of Nicholas Barnewall of Crickeston, Co. Meath, and was the head of a prominent gentry family who became embroiled in the factional disputes between the supporters of James Butler (qv), 4th earl of Ormond, and Richard Talbot (qv), archbishop of Dublin. Barnewall served as the king's serjeant-at-law from December 1420 to April 1429, and again from April 1430 to sometime after July 1432. He also served as deputy treasurer several times (1428, October 1430–March 1431, July 1432–July 1433, March–July 1434, February–March 1436). In 1428 he was one of several Talbot supporters who directed a series of complaints against the lieutenant, Robert Sutton, and the earl of Ormond. He served on several commissions of inquiry.
Barnewall was appointed second justice of the king's bench in Dublin in April 1434. In December 1434 he was granted custody of the lands of the baron of Scryne during the minority of the heir, and then married the heir to his daughter. In February 1435 Barnewall was appointed chief justice of the king's bench, a position he was probably forced to relinquish sometime in 1436. He served as treasurer from June 1437 to November 1437. He was reappointed to the office of chief justice in April 1437 and thereafter held the office for the rest of his life.
Barnewall emerged as a prominent opponent of the earl of Ormond in the early 1440s, and Ormond drew up a series of complaints against him. Barnewall was accused of causing the town of Castledermot to be destroyed by the Gaelic Irish, supporting a rebellion of the commons of Meath and Dublin, advising the archbishop of Dublin not to obey the king's lieutenant in Ireland, defrauding the king of feudal dues by having the young baron of Scryne receive his livery while still under age, and various other crimes. While he was probably guilty of several crimes, Barnewall's conduct was probably no worse than that of any of the other major figures of the day and the accusations do not seem to have affected his tenure as chief justice, which he held till his death in October 1446.