Guppy may stand for:

• Guppy, a popular aquarium fish: Poecilia reticulata
• a series of extremely large wide-bodied aeroplanes that are used to transport oversize cargo. See Pregnant Guppy , Mini Guppy, and Super Guppy.
• the acronym GUPPY in reference to U.S. conventional diesel/electric submarines stands for the Greater Underwater Propulsion Power Program.
• a contemporary slang term referring to "gay yuppy ", implying someone who is overly ambitious in their professional pursuits and highly conscious of maintaining an impeccable image as a slick, modern, urban man.