Although originally a follower of Wesley, he in 1758 adopted extreme Calvinist opinions. He was ordained in 1762 and became vicar of Harpford with Fenn-Ottery, Devonshire, in 1766. In 1768 he exchanged to the living of Broadhembury, Devonshire.
He is chiefly known as a writer of hymns and poems, including "Rock of Ages," and the collections entitled Poems on Sacred Subjects (Dublin, 1759) and Psalms and Hymns for Public and Private Worship (London, 1776). His best prose work is the Historic Proof of the Doctrinal Calvinism of the Church of England (London, 1774).
Some comments by Wesley upon Toplady's presentation of Calvinism led to a controversy which was carried on with much bitterness on both sides. Toplady wrote a venomous Letter to Mr Wesley (1770), and Wesley repeated his comments in The Consequence Proved (1771), whereupon Toplady replied with increased acridity in More Work for Mr Wesley (1772).