Dietmar Lorenz (born September 23, 1950 in Schleiz, Thuringia) is an East German judoka, who competed for SC Dynamo Hoppegarten under the Sportvereinigung Dynamo.
Lorenz won medals at major international competitions, taking gold at the European Judo Championships and the World Judo Championships. He won as the first German the Olympics and the Jigoro Kano Cup. As a member of the East German Olympic team, he took part in the 1980 Summer Olympics in Moscow. These games were boycotted by some countries, including Japan, whose Yasuhiro Yamashita and Sumio Endo were the reigning World Heavyweight and Open Class champions respectively.
He went as an outsider in the "Open Class" at the start. To the surprise of all judo experts, he defeated the favored opponents and also won the final battle against Angelo Parisi of France, who was twelve kilos heavier than him.
Today, he is a trainer at the SC Berlin for children. He wears the nanadan (七段:ななだん): seventh degree black belt (also, shichidan), a component of the Dan rank.