Jean "Bim" Diederich[1] (20 February 1922 – 6 December 2012) was a professional Luxembourgish road bicycle racer, with an impressive record in the Tour de France.

Diederich was born in Esch-sur-Alzette, Luxembourg, and was active in competition from 1946 to 1954.

[1] He had fourteen wins, including stage wins in the 1950 Tour de France (finishing in Menton), the 1951 Tour de France (from Reims to Ghent, leading the race solo over the Muur van Geraardsbergen before crossing the finish line, earning the nickname "Le Duc de Grammont" or "the Duke of Geraardsbergen"), and the 1952 Tour de France (into Namur).

He wore the yellow jersey as leader of the general classification for three days during the 1951 Tour.

This biographical article relating to Luxembourgian cycling is a stub.