This study investigates the thermal decomposition kinetics of Obajana limestone using the Power Rate Law model. The primary objective is to determine the most suitable kinetic parameters, including activation energy and pre-exponential factor, for various calcination temperatures and times. Thermo-Gravimetric Analysis (TGA) was employed to analyze the decomposition process, where calcium carbonate (CaCO₃) decomposes into calcium oxide (CaO) and carbon dioxide (CO₂) in a nitrogen atmosphere. The experimental setup involved varying calcination times (30, 45, 60, and 75 minutes) and applying zero, first, and second-order reaction kinetics. The results indicated that the zero-order kinetic model provided the best fit, with activation energies ranging from 0.308 kJ/mol to 7.367 kJ/mol and pre-exponential factors between 11664.542 mg/min and 17376.26 mg/min. The coefficient of determination (R²) values for the zero-order model were consistently closer to unity, confirming its suitability. These findings contribute to the optimization of calcination processes in industrial applications, offering insights into reactor design and operational parameters for efficient lime production from Obajana limestone.