Mark Gracer P. Isip (born December 10, 1980 in Manila, Philippines) is a Filipino professional basketball player in the Philippine Basketball Association who plays for the GlobalPort Batang Pier. He was drafted sixth overall by Sta. Lucia in the 2006 PBA draft. He only played limited minutes on his first few years until he played for the Barako Bull Energy Boosters during most of the 2010-11 Philippine Cup where he had a number of double-double performances.