Heinrich Klebahn (20 February 1859, Bremen – 5 October 1942, Hamburg) was a German mycologist and phytopathologist.
In 1884 he obtained his PhD from the University of Jena, afterwards working as a schoolteacher in Bremen (1885–1894) and Hamburg (1894-1899). From 1905 onward, he was associated with the botanical gardens at Hamburg. From 1921 to 1934 he was an honorary professor and lecturer of cryptogamy and soil biology at the Institut für Allgemeine Botanik in Hamburg.[1][2]