Cellulosic paper is naturally porous and hydrophilic due to the presence of free hydroxyl groups, which limit its effectiveness in wet environments. Consequently, the industry faces ongoing challenges in developing environmentally friendly and sustainable methods to produce hydrophobic cellulosic paper. In this study, we produced a smooth hydrophobic paper by grafting long-chain oleic acid (OA) onto the cellulose surface through an esterification reaction via a thermochemical process. The chemical composition and surface morphology of the hydrophobic paper were extensively characterized using FTIR, solid-state