A semiconductor package includes a redistribution substrate including a conductive structure having a lower conductive pattern and a redistribution structure electrically connected to the lower conductive pattern, on the lower conductive pattern, an insulating structure covering at least a side surface of the redistribution structure, and a protective layer between the lower conductive pattern and the insulating structure, a semiconductor chip on the redistribution substrate, and a lower connection pattern below the redistribution substrate and electrically connected to the lower conductive pattern. The protective layer includes a first portion in contact with at least a portion of an upper surface of the lower conductive pattern, and a second portion in contact with at least a portion of a side surface of the lower conductive pattern.