Sir Nicholas Barnewall (died after 1465) was an Irish judge and landowner of the fifteenth century who held office as Lord Chief Justice of Ireland. He was the ancestor of the Barnewall Baronets of Crickstown. Nicholas's father was Lord Chief Justice of Ireland for more than a decade. Nicholas was "bred up to the law", and was appointed to the same office as his father in 1457, with a knighthood. In 1461 he was superseded in favour of Sir Thomas Fitz-Christopher Plunket, but regained office later the same year. He retired about 1463, and was still alive in 1465.