Jean-Marie Cadieu (born 16 October 1963 in Tulle) is a former French rugby union player. He played as a lock.
Cadieu played for Stade Toulousain from 1982/83 to 1992/93, where he won 3 titles of the French Championship, in 1984/85, 1985/86 and 1988/89, and a Cup of France, in 1983/84. He then moved to RC Narbonne, where he developed from 1993/94 to 2005/06, when he finished his career.
Cadieu had 12 caps for France, from 1991 to 1992, scoring 1 try, 4 points in aggregate. He played 4 games at the 1991 Rugby World Cup. He had 2 matches at the Five Nations Championship in 1992.