A printed circuit board (PCB) reducing a thickness of a semiconductor package and improving reliability of the semiconductor package, a semiconductor package including the PCB, and a method of manufacturing the PCB may be provided. The PCB may include a substrate base having at least one base layer, and a plurality of wiring layers disposed on a top surface and a bottom surface of the at least one base layer, the plurality of wiring layers defining a plurality of wiring patterns, respectively may be provided. An elastic modulus of a conductive material of one wiring pattern of at least one wiring layer from among the plurality of wiring layers may be less than a conductive material of another wiring pattern.