Recent advancements in composites involve integrating natural fibers into polymer matrices as a reinforcement or filler. This approach offers several benefits, including eco-friendliness, abundant natural materials, exceptional strength, cost-effectiveness, and simple extraction methods. Substituting synthetic materials with natural ones has environmental advantages, as some synthetics release toxins at high temperatures. Natural materials reduce the risk of toxic emissions, fostering a safer environment. Thus, our research centers on experimentally characterizing Fishtail Palm Leaf Stalk Fiber (FPLSF) through methods like Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), single fiber tensile test, and scanning electron microscope (SEM) analysis. These techniques unveil insights into composition, structure, thermal properties, strength, and morphology. Results highlight FPLSF’s attributes: 63.67% cellulose, 1473 kg/m³ density, 380.85 µm diameter, 31.37% crystallinity index, 249.23 MPa tensile strength, and 326°C thermal stability. In addition, the sound absorption properties such as sound absorption coefficient (SAC) and noise reduction coefficient (NRC) are found to be 0.34 and 0.39, respectively. FPLSF’s properties suggest its potential as an alternative reinforcement in composite manufacturing.