A foldable guitar holder has a stationary shaft, a central shaft assembly and two symmetrical brackets. The stationary shaft has an upper end and a lower end. The central shaft has a central shaft and two assistant shafts. The central shaft has a standing portion and a longitudinal hole receiving the lower end of the stationary shaft. The assistant shafts connect pivotally to the central shaft and have two standing ends. The brackets have two supporting shafts and two holding brackets. Each supporting shaft connects pivotally to the lower end of the stationary shaft and one of the assistant shafts and has a standing part. Each holding bracket connects pivotally to the upper end of the stationary bracket. The standing portion, standing ends and standing parts allow the guitar bracket to stand on the ground steadily.