An outer-hanging touch apparatus is hanged on a display apparatus. The display apparatus has a front surface, a top surface, and a rear surface. The outer-hanging touch apparatus includes a touch module and a hanging assembly. The hanging assembly includes a hanging member, an adjusting member, and a driving member. The hanging member is fixed to the touch module and extends to the rear surface. The hanging member includes a guiding structure. The adjusting member is slidably engaged with the guiding structure. The adjusting member abuts against a junction between the top and rear surfaces. The driving member is engaged with the hanging member and the adjusting member for moving the adjusting member relative to the hanging member. When the adjusting member moves toward or away from the touch module along the guiding structure, the hanging member correspondingly moves away from or toward the top surface.