Dennis Geiger is a son of the region. Born in Mosbach and given his footballing education at local club SV Sattelbach, he joined Hoffenheim at U12 level in the summer of 2009. Geiger has played for Germany at every youth level since the U15s and helped his country to a silver medal at the U17 European Championship in Bulgaria in May 2015. During the 2017/18 season, he became a first-team regular, made his debut in the Bundesliga and DFB Cup, and featured in the Champions League play-offs against Liverpool. He prematurely extended his TSG contract until 2022 at the beginning of 2018.