The son of the Irish painter Nathaniel Hone, Horace was born in London. He entered the Royal Academy Schools in 1770, and later established himself as a portrait miniaturist, exhibiting his work at the Royal Academy from 1772 to 1822. In 1782 he moved to Dublin where he had a successful practice, and, in 1795, he was made miniature painter to the Prince of Wales. His practice was badly affected by the 1800 Act of Union, which established the United Kingdom of Great Britain and Ireland, as many of his fashionable patrons moved to London. Hone himself returned to the English capital in 1804, but suffered from mental instability for the rest of his life.