C. G. Conn Ltd., sometimes called Conn Instruments or commonly just Conn, is a former American manufacturer of musical instruments incorporated in 1915. It bought the production facilities owned by Charles Gerard Conn, a major figure in early manufacture of brasswinds and saxophones in the USA. Its early business was based primarily on brass instruments, which were manufactured in Elkhart, Indiana. During the 1950s the bulk of its sales revenue shifted to electric organs. In 1969 the company was sold in bankruptcy to the Crowell-Collier-MacMillan publishing company. Conn was divested of its Elkhart production facilities in 1970, leaving remaining production in satellite facilities and contractor sources.

The company was sold in 1980 and then again in 1985, reorganized under the parent corporation United Musical Instruments (UMI) in 1986. The assets of UMI were bought by Steinway Musical Instruments in 2000 and in January 2003 were merged with other Steinway properties into a subsidiary called Conn-Selmer. C. G. Conn survived as a brand of musical instruments manufactured by Conn-Selmer, retaining several instruments for which it was known: the Conn 8D horn, 88H trombone, 62H bass trombone, 52BSP trumpet and the 1FR flugelhorn.