We present a life detection fluorescence microscope (LDM) for near-future Solar System exploration. The search for extra-terrestrial life in the Solar System is considered a crucial issue in space science. Previously, the NASA Viking mission conducted some life science experiments on Mars in 1976. Other exploration missions have increased our knowledge of Mars. Nevertheless, the presence of life on Mars has not yet been conclusively demonstrated. The LDM uses fluorescence pigments and an excitation light source to identify biological cells, coupled to a microscope for imaging of fluorescent cells. An optical design for this compact microscope is presented herein. We discuss the application of this LDM both for Mars soils and regolith and other targets in the Solar System.