William Lort Mansel (2 April 1753 – 27 June 1820) was an English churchman and Cambridge fellow.

He was educated at the King's School, Gloucester under Edward Sparkes, and at Trinity College, Cambridge (matriculated 1770, scholarship 1771, graduated B.A.

[1] Appointed Bishop of Bristol in 1808 on the recommendation of his former pupil Spencer Perceval, the then Chancellor of the Exchequer,[2] he combined the bishopric with his mastership until his death in 1820.

Lord Byron, who was a student at Trinity from 1805 to 1808,[3] described Mansel ("Magnus", for his corpulence) presiding in college: High in the midst, surrounded by his peers, Magnus his ample front sublime uprears: Plac'd on his chair of state, he seems a God, While Sophs and Freshmen tremble at his nod; As all around sit wrapt in speechless gloom, His voice, in thunder, shakes the sounding dome; Denouncing dire reproach to luckless fools, Unskill'd to plod in mathematic rules.

[5][6] They had 13 children:[7] On Mansel's death, his executors were Edward Daniel Clarke and James Devereux Hustler; his estate was left in will to his five unmarried daughters.