John Seally (1741 or 1742–1795) was an English writer, in later life a clergyman.^[1]

Born in Somerset, he was educated at Bristol grammar school, with a view to ordination. His uncle and potential patron died, and he entered a solicitor's office; but moved on to learn business under the merchant Malachy Postlethwayt. Supported by his mother, he then became a journalist.^[2]

During a visit to Manchester, Seally persuaded an heiress to elope with him but her father caught up with them at Worcester. He worked as a writing-master and accountant. Around 1767 he established a school in Bridgwater Square, Westminster, and after some years took holy orders. During a stay in Rome in 1774 he obtained admission to the Accademia degli Arcadi by a eulogy on Maria Maddelana Fernandez Corilla, poet-laureate of Italy. In 1790 he was presented to the vicarage of East Meon with Froxfield and Steep.^[2]

Seally was elected fellow of the Royal Society on 30 June 1791, and was also M.A. and LL.D. He died in Queen Square, Westminster, in March 1795.^[2] A correspondent in the Evangelical Magazine mentioned that Seally had been chaplain to the Earl of Kintore, was buried in Ellisfield, Hampshire, and was aged 49 on his death.^[3]

Seally published novels, poems, and school books, including:^[2]

• The Loves of Calisto and Emira, or the Fatal Legacy, London, 1776; a French translation was published in Paris (1778).
• Moral Tales after the Eastern manner, London (1780?).
• The Marriage of Sir Gawaine, an opera, 1782.
• A complete Geographical Dictionary, 2 vols., London, 1787. The astronomical section was provided by Israel Lyons.^[4]
• The Lady's Encyclopaedia, 3 vols., London, 1788.

He contributed occasional verses to magazines, and launched a short-lived political paper signed Britannicus. He ran for some time the Universal Museum and the Freeholder's Magazine, and was involved in the St. James's Magazine, edited by Robert Lloyd.^[2]

Seally married (as he thought) in 1766, a reputedly rich widow of twice his age, but found, some years later, that she had no money and had a husband, the Rev. William Lewis. After separation from Mrs. Lewis he married Mary, eldest daughter of Joseph Humphreys, rector of Ellisfield, Hampshire, and of North Stoke, Somerset, who survived him.^[2]