RSG Group LLC is a German, internationally active fitness group founded in 1996 by Rainer Schaller. The registered office is in Schlüsselfeld, Germany, and the administrative headquarters are in Berlin, Germany. The group's best-known brands are the Gold's Gym, McFit and John Reed studio chains. In the United States, the company operates under RSG Group North America LP and RSG Group USA Inc.

Rainer Schaller was a German entrepreneur. He was the Founder CEO of the RSG Group, which includes the McFit, John Reed Fitness and Gold's Gym fitness studios. He hit headlines as a result of the disaster at the 2010 Love Parade in Duisburg, which he organized. On 21 October 2022, Schaller and his son Aaron died in a private plane crash in Costa Rica.