A semiconductor package is provided. The semiconductor package may include a substrate, a chip stack disposed on the substrate, the chip stack including a plurality of semiconductor chips, a plurality of bonding wires electrically connecting the substrate to the plurality of semiconductor chips, a reinforcement layer disposed on the chip stack, and a molding layer surrounding side surfaces of the chip stack and the bonding wires and contacting side surfaces of the reinforcement layer. The reinforcement layer may include a lower layer including an adhesive, an intermediate layer disposed on the lower layer, and an upper layer disposed on the intermediate layer. The intermediate layer may have elongation in a range of 5% to 70%. The upper layer may have elongation less than 5%.