Denis Gremelmayr (born 16 August 1981) is an inactive German male tennis player. His career-high singles ranking is World No. 59, achieved in May 2008.
Glemelmayr was born in Heidelberg, Baden-Württemberg. He reached the semifinals of Estoril, Barcelona and Los Angeles in 2008, losing to Roger Federer, Rafael Nadal and Andy Roddick respectively.