This paper presents a precise geoid (PNU95 Geoid) over the southern half of the Korean peninsula. The geoid using the OSU91A reference gravity model to degree and order of 167 with an integration radius of 27 km fits to the well-distributed 71 GPS data best. The RMS difference between the modeled geoid and the GPS/leveling-implied geoid is 0.15 m, and its accuracy with respect to the GPS/leveling distance is 1.1 ppm. The resulting PNU95 Geoid varies from 21.8 m at the western part of the peninsula, Kanghwa-Do, to 30.2 m at the south-eastern part. Kyungju, generally increasing eastward.