Joseph Barber Lightfoot (sometimes called J. B. Lightfoot; 13 April 1828 – 21 December 1889) was an English theologian and Bishop of Durham.
Lightfoot was born in Liverpool, where his father was an accountant. He was educated at King Edward's School, Birmingham, under James Prince Lee. His contemporaries included Brooke Foss Westcott and Edward White Benson. In 1847 Lightfoot went to Trinity College, Cambridge, and read for his degree along with Westcott. He graduated senior classic and 30th wrangler, and was elected a fellow of his college. From 1854 to 1859 he edited the Journal of Classical and Sacred Philology. In 1857 he became tutor and his fame as a scholar grew. He was made Hulsean professor in 1861, and shortly afterwards chaplain to the Prince Consort and honorary chaplain in ordinary to Queen Victoria.
In 1866 he was Whitehall preacher, and in 1871 he became canon of St Paul's Cathedral. The Times wrote after his death that:
It was always patent that what he was chiefly concerned with was the substance and the life of Christian truth, and that his whole energies were employed in this inquiry because his whole heart was engaged in the truths and facts which were at stake.
In 1875 Lightfoot became Lady Margaret's Professor of Divinity in succession to William Selwyn. In 1879 he was consecrated bishop of Durham in succession to Charles Baring; he was enthroned at Durham Cathedral on 15 May. He soon surrounded himself with a band of scholarly young men.
Lightfoot was never married. He died at Bournemouth and was succeeded in the episcopate by Westcott, his schoolfellow and lifelong friend. He served as President of the first day of the 1880 Co-operative Congress.