John Jebb (7 September 1775 – 9 December 1833) was an Irish churchman and writer.
He was born in Drogheda, younger son of John Jebb senior, an alderman of the town of Drogheda, and Alicia Forster. His father had an estate at Leixlip in County Kildare: his grandfather Richard Jebb had come to Ireland from Nottinghamshire. His father was in reduced financial circumstances for a time, but later recovered his fortunes, and at his death in 1796 left John £2000. He was educated at the local school in Celbridge, then at Free Grammar School, Derry (later renamed Foyle College, now part of Foyle and Londonderry College) where he formed a lifelong friendship with the theologian Alexander Knox, and at Trinity College Dublin.
Ordained in 1799, he became curate of Swanlinbar, County Cavan and later curate in Mogorbane, County Tipperary in 1805, archdeacon of Emly in 1801. In 1805 he became private chaplain to Charles Brodrick, Archbishop of Cashel, and in 1809 he became rector of Abingdon, County Limerick, where his curate was Charles Forster, his lifelong friend and first biographer. He spent some time in England, where he became a friend of William Wilberforce and of Hannah More. In 1812 he was seriously injured in a carriage accident; the injuries were poorly treated by his medical advisers, and he probably never fully recovered his health.