The use of fiber in mortar/concrete is now common for enhancing the flexural and ductility properties of structures. However, the utilization of synthetic fibers contributes to the emission of harmful greenhouse gases. Replacing these synthetic fibers with natural fibers derived from waste plants is imperative for sustainable development. The objective of this study was to evaluate the performance of short and thin banana fibers in enhancing the mechanical properties of fiber-reinforced mortar, specifically in terms of compressive, flexural, and splitting tensile strengths. The base mortar, with a water-cement ratio of 0.30 and a unit water content of 298 kg/m3, was employed. The banana fibers were manually extracted from banana stalks, dried in an oven, and then cut into 10 mm fibers. The fibers were not treated with alkali. The fiber content was varied at 0 %, 0.125 %, 0.25 %, 0.5 %, and 0.75 % by weight of cement. Initially, the fibers were mixed into the viscous mortar along with the first portion of water and a superplasticizer. Subsequently, workability was improved by incorporating the second portion of water. The optimal content of banana fiber was determined to be 0.25 %, which increased the 28-day compressive, flexural, and splitting tensile strengths by 18.7 %, 29.9 %, and 41.1 %, respectively, compared to the base mortar. These findings suggest that the short and thin banana fiber has the potential to serve as a sustainable alternative to synthetic fibers. However, it is essential to conduct a thorough assessment of durability properties before implementing it in actual structures.