A semiconductor package includes a package substrate, a semiconductor chip on the package substrate, a heat dissipation structure on the package substrate, the heat dissipation structure including a center portion and an edge portion, a dam structure on a bottom surface of the center portion of the heat dissipation structure, the dam structure on a top surface of the semiconductor chip, and a heat conductive layer between the center portion of the heat dissipation structure and the semiconductor chip. A top surface of the dam structure is located at a same distance from a top surface of the package substrate in a vertical direction as a top surface of the heat conductive layer, wherein the vertical direction is perpendicular to the top surface of the package substrate.