Janassa is an extinct genus of petalodont cartilaginous fish that lived in marine environments in what is now central United States of America and Europe during the Carboniferous and Permian. It is known from teeth and a few poorly preserved body fossils from Germany (Kupferschiefer, Upper Permian) and England (Marl Slate, Upper Permian). According to the fossils, Janassa had a body plan very similar to that of the modern skate.