A semiconductor package includes a substrate, first to third semiconductor chips disposed on the substrate, first to third heat transfer components, first and second heat spreaders, and a trench. The first semiconductor chip is between the second and third semiconductor chips. The first to third heat transfer components are disposed on the semiconductor chips, respectively. The first heat spreader is formed on the first to third heat transfer components. The second heat spreader protrudes from the first heat spreader. The trench is formed on the second heat spreader. The second heat spreader includes first and second side units spaced apart with the trench between. A distance between an outer surface of an uppermost part of the first side unit and an outer surface of an uppermost part of the second side unit is smaller than a width of an upper surface of the first semiconductor chip.