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