Gamma (Γ γ) is the 3rd letter of the Greek alphabet and has a numeric value of 3.

It gives its name to several things:

• Gamma characteristic power law, and gamma correction in television and computer display systems. gamma refers to the exponent in a power-law relationship between video or pixel values and the displayed brightness.
• In the game of Tetris, gamma is another name for the J tetromino.

• The gamma function (related to factorials) in mathematics.