A semiconductor package includes a substrate, at least one semiconductor chip arranged in the substrate and having chip pads, and a redistribution wiring layer covering a lower surface of the substrate and including first and second redistribution wirings and dummy patterns, the first and second redistribution wirings being stacked in at least two levels and connected to the chip pads. The first and second redistribution wirings are arranged in a redistribution region of the redistribution wiring layer, and the dummy patterns extend in an outer region outside the redistribution region to partially cover corner portions of the redistribution wiring layer, respectively.