The impact of the excessive accumulation of dyes like methylene blue (MB) in the environment has posed a challenge to both researchers and scientists. Due to the recalcitrant nature of the dye, the implementation of an advanced oxidation process in wastewater paves the way for the development of a sustainable photocatalyst. Here, the photocatalytic degradation of MB using hydroxyapatite (HAp) from Tilapia (Oreochromis niloticus) fish bone as a photocatalyst was investigated. The Hap was synthesized via calcination under simple heat treatment at 900^oC with 5/min heating rate. The physicochemical properties of the synthesized HAp were characterized using Fourier Transform–Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and X-ray Diffractometer (XRD). The photocatalytic degradation of MB was conducted at varying initial pollutant concentrations (8 and 12 ppm), catalyst loadings (500 and 1000 mg), and time exposures (1 and 2 hr). Results showed that the HAP exhibited an agglomerated formation of a non-uniform nano-spherical crystal powder. FTIR confirmed the presence of functional groups associated with Hap, while the XRD spectra demonstrated peaks at 31.70°, 32.84°, and 32.12°, confirming the formation of Hap. Finally, the highest photocatalytic degradation of 84.75% was obtained with 12 ppm initial concentration and 1000 mg catalyst loading subjected to a 2 hr UV irradiation time, showing the potential of mitigating the impact of MB dye in the environment.