William Kelly (May 1821 - 27 March 1906) was a prominent Northern Irish member of the Plymouth Brethren, amongst whom he was a prolific writer. Kelly was born in Millisle, County Down, Northern Ireland. He was educated at Trinity College, Dublin. Left fatherless at a young age, he supported himself by teaching the family of Mr. Cachemaille, Rector of Sark. He secured a post as governor to the Seigneur of Sark in 1841. He married in Guernsey and in the 1870s moved to Blackheath, London. In 1840 Kelly made the Christian confession and, shortly afterwards, embraced the views of, and became a member of, the Plymouth Brethren. He retained a close connection with the Channel Islands for thirty years, residing chiefly in Guernsey. Besides aiding Dr. Samuel Prideaux Tregelles in his investigations as a Biblical textual critic, Kelly also published, in 1860, a critical edition of the Book of Revelation, which was praised by Professor Heinrich Ewald of Göttingen. Such studies were carried on concurrently with the editing of a periodical entitled The Prospect. He took up the editorship of The Bible Treasury in 1857, and continued till his death. As editor of the latter he was brought into correspondence with Dean Henry Alford, Dr Scott the lexicographer, Principal Edwards and William Sanday of Oxford, among others. Kelly died on 27 March 1906. Shortly before his death, Kelly said "There are three things real — the Cross, the enmity of the world, the love of God."