A method of fabricating a semiconductor package includes providing a semiconductor chip, forming a redistribution substrate, and fabricating a package including the semiconductor chip disposed on the redistribution substrate. The forming of the redistribution substrate may include forming a first insulating layer on a substrate, the first insulating layer having a first opening formed therein, forming an integrally formed first redistribution pattern in the first opening and on the first insulating layer, forming a second insulating layer on the first insulating layer to cover the first redistribution pattern, and performing a planarization process on the second insulating layer to expose the first redistribution pattern.