Variability of feedstock and inefficiency of catalysts are usually limiting factors in the sustainable production of biodiesel using waste resources. In the present study, the strategy of same-source waste valorization was applied whereby the waste chicken fat oil was treated as the biodiesel feedstock and the waste chicken bones were subjected to controlled calcination (400-1000^oC) and potassium hydroxide (KOH) activation to obtain a heterogeneous base catalyst. Physicochemical examination of the chicken fat oil indicated high kinematic viscosity (49.49mm²s^-1 at 40^oC), middle free fatty acid level (1.96%), low moisture level (0.079%), low peroxide value (5.63 meqkg^-1), and high fraction of the esterifiable, which confirmed that it is suitable in heterogeneous base-catalyzed transesterification. Fourier-transform infrared (FTIR) analysis of the feedstock confirmed the presence of typical triglyceride functional groups, strong ester carbonyl (C=O) and aliphatic C-H stretching vibrations which are characteristic of a high esterifiable lipid fraction. The GC-MS analysis also revealed that the chicken fat oil was mainly composed of saturated and monounsaturated fatty acids with palmitic and oleic acids as the prominent components, which are desirable in the biodiesel production and ignition properties. The biodiesel yield, improvement of fuel properties, and reproducibility of the processes were used to evaluate the performance of catalysts. The temperature of calcification had a strong impact on catalytic activity, and 800^oC was the best temperature to ensure the balanced basicity of the surface and structural stability, and the activation of the catalyst using KOH further increased catalytic activity. A batch reactor experiment showed that the highest biodiesel yield (>80%) was obtained at a catalyst concentration of 1.0 wt%, methanol-to-oil molar ratio of 12:1, reaction temperature of 60^oC, reaction time of 2h, and agitation rate of 400 rpm. The biodiesel produced had a kinematic viscosity of 7.5-8.9 mm² s^-1, a specific gravity of 0.874-0.887, a flash point of 160-181^oC, and cetane index of more than 52 which showed good ignition quality. Upon purification, the fuel properties were observed to be near to the specifications of ASTM D6751 and EN 14214. In general, the findings indicate that the calcined and KOH-activated chicken bone waste is an efficient, inexpensive heterogeneous catalyst in the production of biodiesel out of waste chicken fat oil, which will contribute to the creation of the circular biofuel and reduce the amount of waste.