In the present research, an attempt had been made to utilize durian shell as a carbon source for catalyst support in transesterification of palm oil (PO). The objective of this research was to explore durian shell as a carbon source for catalyst support, its modification with KOH, as well as its characterization and application in transesterification of PO. Prior to usage, durian shell was calcined at 600℃ for 2 h in a furnace. Carbon formed was impregnated in KOH solution, followed by drying and calcination. The resulting activated carbon was characterized by SEM-EDX, FTIR, and BET. The activated carbon was then utilized as a solid catalyst in biodiesel formation. Transesterification was conducted at 55 to 70℃, methanol to PO molar ratio (MPR) of 12:1, catalyst load of 2-5%, and reaction time of 90-150 min. The highest biodiesel yield of 97.3% was reached using 3% catalyst load at 60℃ for 90 min. Biodiesel obtained in this work was then characterized for its chemical physical properties. The biodiesel properties met the European standard (EN-14214). The results suggested that durian shell based activated carbon is applicable as a solid catalyst for biodiesel synthesis