SrTi0.97 Ni0.03O3 photocatalysts with varied sintering temperatures of 900°C and 1000°C have been successfully prepared via the co-precipitation method. This study aimed to determine the effect of temperature on SrTi0.97 Ni0.03O3 photocatalyst including the microstructure, atomic bonding, and photocatalyst activity. X-Ray Diffraction (XRD) data revealed an increase in the crystallite size with increasing the sintering temperature. Fourier Transform Infrared (FTIR) results confirmed the formation of Sr-Ti-O bonds followed by the presence of CH impurities that the impurities decreased at 1000°C. The photocatalyst activity was tested using methylene blue (MB) degradation in SrTi0.97 Ni0.03O3 photocatalysts under UV rays. The time for the irradiation process varied from 3, 4, to 5 hours. The degraded result was examined using a UV-Vis spectrophotometer to estimate the %degradation. The results demonstrated that the sintering temperatures do not considerably impact MB degradation. Further, the best treatment for SrTi0.97Ni0.03O3 to attain the highest MB degradation of 49.9% is at 900°C with 5 hours of irradiation.