A head-mounted display apparatus including a light source module, an optical adjustment element, a display module and a lens element is provided. The light source module provides an illumination beam. The optical adjustment element and the display module are disposed on a transmission path of the illumination beam, and the display module is configured to convert the illumination beam into an image beam. The optical adjustment element is located between the light source module and the display module. The lens element is disposed on a transmission path of the image beam, wherein a transmission direction of the maximum light-emitting intensity of the illumination beam transmitted from the light source module to the optical adjustment element is different to a transmission direction of the maximum light-emitting intensity of the illumination beam transmitted from the optical adjustment element to the display module.