The 230 J was a small class of 4-6-0 steam locomotives of the Chemin de Fer de l'État.
The series of 20 engines was built in 1910 with 2.04 m diameter wheels. They were coupled with 21 cubic metre tenders. These machines, liked by drivers of the Chemin de Fer de l'État, were nicknamed Jocondes.
In 1936, these engines were modified and streamlined. Fireboxes were enhanced which permitted higher pressures as well as better heat dispersion. This enabled the engines to travel at speeds of up to 120 km/h with trains of 300 tons.
The engines, numbered 230-781 to 230-800 with the Chemin de Fer de l'État were renumbered 230 J 781 to 800 by the SNCF in 1938.