The aim of this study is to explore the potential of CASCABELA thevetia (CT) bast fibers as reinforcement in polymer composites. For this purpose, the extracted fibers were chemically treated with various chemicals such as sodium hydroxide, potassium permanganate, sodium chlorite, and benzoyl chloride. After surface modifications, its physical and mechanical properties, chemical composition, and structure were studied. The X-ray diffraction (XRD) results revealed an increase in crystallinity index of the fibers as compared to untreated fibers with benzoyl chloride treated fibers showing the optimum result which agrees with the results obtained in the mechanical tests. Composites were fabricated by taking various wt.% of benzoyl chloride treated CT fibers in an epoxy matrix (i.e. 5, 10, 15, 20, 25, and 30 wt%) and their mechanical and wettability tests were carried out. It was observed that composites with 20 wt% of fiber loading show the highest mechanical properties (52.79 MPa tensile strength, 2.45 GPa Young's modulus, 71.72 MPa flexural strength). All the fabricated composites showed contact angle less than 90°, which is associated with composite hydrophilic surface properties. These composites can be utilized in lightweight structural material and in automobile industries owing to its better properties.