Heinrich Simon Ludwig Friedrich Felix Rehm (20 October 1828, Ederheim – 1 April 1916, Munich) was a German mycologist and lichenologist.He studied at the Universities of Erlangen, Munich and Heidelberg, earning his medical doctorate in 1852. During his career, he was a practicing physician in Dietenhofen (from 1854), Sugenheim (from 1857) and Windsheim (from 1871). In 1875 he became regional medical examiner in Lohr am Main.