Thomas Fahrner (born 7 February 1963 in Ludwigshafen, Rhineland-Palatinate) is a former freestyle swimmer from West Germany. At the 1984 Summer Olympics in Los Angeles Fahrner earned two medals bronze in the 200 m freestyle and silver in 4×200 m freestyle relay. He also set an Olympic record for the 400 m freestyle (3:50.91) in the B final. Four years later at the 1988 Summer Olympics in Seoul he earned another medal this time a bronze medal in the 4×200 m freestyle relay. Fahrner attended the University of Southern California.