In this research, kenaf core fibre (KCF) reinforced unsaturated polyester resin (UPE) biocomposites were produced by introducing graphene nanoplatelet (GNP) as nanofiller at a total loading of 3.0 wt%. The purpose of GNP incorporation is to produce a better performance of the UPE biocomposite since KCF alone is not giving a promising result in terms a mechanical and thermal properties. GNP/KCF-UPE biocompositos were successfully fabricated using compression moulding. For comparison purposes, pure UPE and UPE-KCF samples are produced along with other samples with the inclusion of the various amounts of GNP nanofiller, varying from 0.5 wt% to 3.0 wt%. All samples were characterized under several testing which is a flexural test, therrnogravimetric analysis ((GA), and scanning electron microscopy (SEM) for mechanical, thermal, and morphological characterization, respectively. The mechanical testing shovved that UPE-KCF biocomposite with the addition of 1.5 wt% of GNP demonstrated a significant result of flexural strength and modulus. The thermal properties of the biocomposites also showed a good increment of thermal stability along with the highest loading of GNP. Morphological studies carried out with scanning electron microscopy revealed various fracture surface morphology of GNP reinforced KCF-UPE biocomposites which could be related to their mechanical properties results. Keyword: Unsaturated polyester resin, kenaf core fibre, graphene nanoplatelet, mechanical properties, thermal properties.