Red bug may refer to:
Tegastes acroporanus a coral parasite, known in the reef-keeping hobby as "red bugs" Red Bug, North Carolina Auto Red Bug, an automobile manufactured 1916-1920 by the American Motor Vehicle Company in Lafayette, Indiana Pyrrhocoridae, a family of insects Smith Flyer, an automobile manufactured 1915-1919 by the A.O. Smith Company in Milwaukee, Wisconsin Trombicula, a genus of harvest mites