In this study, a new eutectic solvent (ES) was synthesised for the first time via mixing (1R)-(-)-camphor-10-sulphonic acid (10-CSA) with choline chloride (ChCl). Camphor-10-sulphonic acid choline chloride eutectic solvent (CSA-ChCl-ES) was used as a catalyst in the esterification reaction of an oil mixture consisting of acidic crude palm oil and sludge palm oil in order to reduce the free fatty acid (FFA) content to less than 2%. The optimal reaction conditions were as follows: 2.5 wt% of catalyst dosage, 10:1 molar ratio, 60°C of reaction temperature and 40 min of reaction time. This study revealed that the novel eutectic solvent possessed high catalytic activity and recyclability, hence highlighting its high potential for biodiesel production.