Frederick Oakeley (5 September 1802 – 30 January 1880) was an English Roman Catholic convert, priest, and author. He was ordained in the Church of England in 1828 and in 1845 converted to Catholicism, becoming Canon of Westminster in 1852. He is now best known for his translation of Adeste Fideles (O Come All Ye Faithful) into English.
The youngest child of Sir Charles Oakeley, 1st Baronet, he was born on 5 September 1802 at the Abbey House, Shrewsbury. In 1810 his family moved to the bishop's palace at Lichfield. Poor health prevented his leaving home for school, but in his fifteenth year he was sent to Charles Sumner for tuition. In June 1820 he matriculated at Christ Church, Oxford; he gained a second class in literæ humaniores in 1824. After graduating B.A. he won the chancellor's Latin and English prize essays in 1825 and 1827 respectively, and the Ellerton theological prize, also in 1827.
In 1827 he was ordained, and was elected to a chaplain fellowship at Balliol College. In 1830 he became tutor and catechetical lecturer at Balliol, and a prebendary of Lichfield on Bishop Henry Ryder's appointment. In 1831 he was select preacher, and in 1835 one of the public examiners to the university. The Bishop of London, Charles Blomfield; appointed him Whitehall preacher in 1837, when he resigned his tutorship at Balliol, but he retained his fellowship.
During his residence at Balliol as chaplain-fellow (from 1827) Oakeley became connected with the tractarian movement. Partly under the influence of William George Ward, he had grown dissatisfied with evangelicalism, and in the preface to his first volume of Whitehall Sermons (1837) he avowed himself a member of the new Oxford school. In 1839 he became incumbent of Margaret Chapel, the predecessor of All Saints, Margaret Street, and Oxford ceased to be his home.