Jacques Denys (Denis) Choisy (5 April 1799, Jussy – 26 November 1859, Geneva) was a Swiss Protestant clergyman and botanist.He studied theology, law, humanities and sciences at the Académie de Genéve. In 1821 he became ordained as a minister, and during the following year, furthered his education in Paris. During his stay in Paris, he was accepted as a member of the Société d'histoire naturelle.