This paper reports the morphological, physical, chemical, mechanical and thermal properties of untreated and various chemically treated natural fibers extracted from the petioles of the Phoenix sp. plants. The outcome of morphological analysis revealed that the treated Phoenix sp. fibers have tiny protrusions on its surface which promotes the mechanical interlocking between fiber and matrix. The physical and chemical analysis ensured that the chemical treatments had a positive impact. The chemical functional groups present in the Phoenix sp. fibers were confirmed through FTIR analysis. The improvement in crystallinity index values of treated fibers was confirmed through X-ray diffraction analysis. The fiber treated with acrylic acid exhibited the highest tensile strength and tensile modulus of 466.35 MPa and 9.26 GPa, respectively. The thermal stability of the Phoenix sp. fiber was examined through thermogravimetric analysis and it revealed that the treated fibers have better thermal stability. The above results concluded that the Phoenix sp. fiber is an appropriate reinforcement material for preparing polymer matrix composites.