Disclosed are semiconductor packages and methods of fabricating the same. The semiconductor package comprises a first wiring layer, a first semiconductor substrate on the first wiring layer, a first dielectric layer on the first semiconductor substrate, a landing pad in the first wiring layer, a through hole that penetrates the first semiconductor substrate, the first dielectric layer, and the first wiring layer and exposes the landing pad, the through hole including a first hole and a second hole on a bottom end of the first hole, the second hole having a maximum diameter less than a minimum diameter of the first hole, and a mask layer on an upper lateral surface of the through hole.