Henry Lemoine (1756–1812) was an English author and bookseller.
From a Huguenot background, he was born in Spitalfields 14 January 1756, and baptised in the French church De La Patente in Brown's Lane there, 1 February 1756. He was the only son of Henry Lemoine who had left Normandy for Jersey, who died in April 1760; his mother, Anne I. Cenette, was a native of Guernsey. He was educated at a free school run French Calvinists in the East End of London, and in 1770 was apprenticed to a stationer and rag merchant in Lamb Street, Spitalfields.
From Spitalfields Lemoine moved about 1773 to the shop of a Mr. Chatterton, a baker and bookseller. He then became for a time French master in a boarding-school at Vauxhall, kept by one Mannypenny, a post lost by the hoax that he was incapable of speaking a word of English. On coming of age in 1777 he inherited property in Jersey, purchased a bookstall in the Little Minories, and began writing for magazines. He also dispensed drugs, including the "bug-water" of Thomas Marryat's recipe.
In 1780 Lemoine moved to a stand in the churchyard at Bishopsgate, Churchyard, and became acquainted with David Levi the Jewish apologist, whom he supplied with materials for his controversy with Joseph Priestley. About this period he met with Levi and other writers at the house of George Lackington in Chiswell Street. On 8 October 1788 he was admitted a freeman of the Leathersellers Company by redemption.
In 1792 Lemoine started the Conjurors' Magazine, with embodied a translation of the treatise on physiognomy by Johann Kaspar Lavater. It sold well, but by 1793, when it became known as the Astrologer's Magazine, Lemoine's connection with it had practically ceased; it did include reprints of some stories of his from the Arminian Magazine and elsewhere. In 1793 he started the Wonderful Magazine and Marvellous Chronicle, to which he contributed biographies including one of Baron Diego Pereira d'Aguilar.