Henry Thomson RA (31 July 1773 – 5 April 1843) was an English artist and Royal Academician who became Keeper of the Royal Academy.
As a painter, he specialized in historical, mythological and literary subjects. He was also a translator.
Born in Portsea, Portsmouth, Thomson was the son of a naval purser who encouraged his son's interest in art and took him to Paris in 1787. They returned to England two years later, as a result of the French Revolution. From 1791 to 1792, Thomson attended the Royal Academy Schools. He then continued to train under John Opie, before travelling again in Europe with his father. They were in Italy between 1793 and 1798, then in Austria and Germany in 1799. After his return to England later that year, Thomson's artistic career made speedy progress. In the Royal Academy exhibition of 1800 he exhibited paintings of classical subjects. The following year he was elected an associate member of the Academy and in 1804 an Academician.
Although primarily a historical painter, like most of the artists of his time Thomson relied heavily on income from illustrating books. His reputation was established in 1801-02 with his work for Boydell's Shakespeare Gallery. He exhibited many mythological and domestic paintings, and also portraits, until 1825.
He was appointed Keeper of the Royal Academy in 1825, succeeding Henry Fuseli, but after only two years he resigned on the grounds of severe illness, when he was succeeded as Keeper by William Hilton. He never recovered and took on no further significant work, retiring to Portsea and dying there on 6 April 1843. He was buried in the churchyard of the Portsmouth parish church.