Jean Joseph Étienne Lenoir (January 12, 1822 - August 4, 1900) was a Belgian engineer who developed the an internal combustion engine in 1859. Prior designs for such engines were patented as early as 1807, but none were commercially successful. Lenoir's engine was commercialized in sufficient quantities to be considered a success, a first for the internal combustion engine.
He was born in Mussy-la-Ville (then in Luxembourg, part of Belgium from 1839). By the early 1850s he had emigrated to France, taking up residence in Paris, where he developed an interest in electroplating. His interest in the subject led him to make electrical inventions including an improved electric telegraph.