John Law (1745–1810) was an English mathematician and clergyman who began his career as a Fellow of Christ's College, Cambridge, and went on to become chaplain to the Lord Lieutenant of Ireland and Church of Ireland bishop of Clonfert and Kilmacduagh (1782–1787), Killala and Achonry (1787–1795), and finally of Elphin (1795–1810).
He was a lifelong friend and correspondent of the philosopher William Paley.