John Callcott Horsley (January 29, 1817 - October 18, 1903), English painter, son of William Horsley, the musician, and grand-nephew of Sir Augustus Callcott, was born in London.

He studied painting in the Academy schools, and in 1836 exhibited "The Pride of the Village" (Vernon Gallery) at the Royal Academy. This was followed by numerous genre pictures at subsequent exhibitions up to 1893, the best known of these being "Malvolio," "L'Allegro and il Penseroso" (painted for the Prince Consort), "Le Jour des Morts," "A Scene from Don Quixote," etc.

In 1843 his cartoon of "St Augustine Preaching" won a prize in the Westminster Hall competition, and in 1844 he was selected as one of the six painters commissioned to execute frescoes for the Houses of Parliament, his "Religion" (1845) being put in the House of Lords; he also painted the "Henry V assuming the Crown" and "Satan surprised at the Ear of Eve." In 1864 he became RA, and in 1882 was elected treasurer, a post which he held till 1897, when he resigned and became a "retired Academician."

Horsley designed the first ever Christmas card, commissioned by Henry Cole. It caused some controversy because it depicted a small child drinking wine. He also designed the Horsley envelope , a pre-paid envelope that was the precusor to the postage stamp.

Horsley had much to do with organizing the winter exhibitions of "Old Masters" at Burlington House after 1870. When, during the 'eighties, the example of the French Salon began to affect the Academy exhibitors, and paintings of the nude became the fashion, he protested against the innovation, and his attitude caused Punch to give him the punning sobriquet of "Mr J C (lothes) Horsley."

His son, Sir Victor Horsley (b. 1857), became famous as a surgeon and neuropathologist, and a prominent supporter of the cause of experimental research.