G大调是一个基于G音的大调，由G、A、B、C、D、E、升F（F♯）、G组成，调号有一个升号。相对小调是E小调，并行小调是G小调。

于高音谱号中，F的升号多写在五线谱最上的线。但在一些巴洛克时期的音乐中会写在最下的空位（即低八度的F音）。

G major (or the key of G) is a major scale based on G, with the pitches G, A, B, C, D, E, and F♯. Its key signature has one sharp, F♯.

G major's relative minor is E minor, and its parallel minor is G minor.

For orchestral works in G major, the timpani are typically set to G and D, a fifth apart, rather than a fourth apart as for most other keys.