The present disclosure relates to a garment folding apparatus, which serves to fold a garment during a process of conveying the garment, the garment folding apparatus including a loading assembly configured to load the garment, a folding assembly configured to fold the loaded garment while conveying the garment, and an unloading assembly disposed below the folding assembly and configured to unload a completely folded garment, in which the folding assembly comprises a vertical folding assembly configured to actively fold the garment deployed on a conveyor by using a drive motor, such that a vertical folding operation is performed along a rectilinear trajectory, which makes it possible to reduce a required operation space and contribute to miniaturization of the apparatus.