The aim of this research is to see whether coconut tree peduncle fiber (CTPF) can be used as a potential polymer composite reinforcement. The cellulose content (50.11 wt.%) provides a strong single fiber tensile strength (137 MPa) to CTPF, and the surface morphology shows porous surface, thereby promoting better bonding with the matrix. The higher crystalline size and semi-crystalline nature of CTPF highlighted its low density (1.360 g/cm3) and water absorption properties. Lignin (24.9 wt.%), combined with a low wax content (0.3 wt.%) and presence of porous surfaces and microfibrils found by scanning electron micrographs, allows for stronger bonding between the matrix and fibers. With the existence of chemical groups detected by Fourier transform infrared analysis, the low density (1.360 g/cm3), semi-crystalline nature (52%), and larger crystalline size (6.5 nm) guarantees the least water absorption characteristics. Furthermore, CTPF’s thermal stability above the polymerization process temperature was verified using differential scanning calorimetric (DSC) and thermo-gravimetric analysis (TGA). As a result, CTPF’s properties make it a good candidate for use as a bio-reinforcement in polymer composites for lightweight and structural applications.