Natural fibers have been identified as reinforcing materials in polymer composites to fabricate sustainable materials. Natural fibers have low density compared to synthetic fibers, resulting in high specific strength and stiffness, making them useful as lightweight reinforcing materials and composites. In the current study, the properties of locally available pineapple leaf fibers (PALFs) have been investigated for their potential as a reinforcement in sustainable polymer composites. The fibers were extracted using the water retting method. Alkali treatment has been performed using 5 wt.% of NaOH solution to make the fibers compatible with the polymeric matrix phase. The diameter of the fibers is measured as 234 ± 33.50 µm and 190 ± 34.01 µm before and after treatment, respectively. The FTIR and EDX results show the removal of hemicellulose, lignin, and impurities present on the fiber surface. The tensile strength of raw and treated fibers is measured as 252.14 ± 12.35 MPa and 296.62 ± 14.21 MPa. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are utilized to examine the surface topography of the treated and untreated fibers.