Big G may refer to:
Geography Big G, an attraction in Gracemere, Queensland, Australis The Big G, a landmark in Glasgow, Scotland, set up for the 2014 Commonwealth Games
People Jason Giambi, American baseball player Giancarlo Stanton, American baseball player
Other uses Big Gemini, an advanced version of the Gemini program spacecraft system Gravitational constant, a physical constant involved in the calculation of gravitational effects Takeshi "Gian" Goda, a character from Doraemon, referred to as "Big G" in English language adaptations
See also G, the letter General Mills