Pyrolysis has considerable potential for the monetization and management of neem seedcake by producing value-added compounds. The decomposition of neem seedcake (NSC) was analyzed, occurs in three stages: moisture removal (30–220°C), active decomposition (220–550°C), and slow char formation (550–800°C). The activation energies for seedcake pyrolysis were calculated using the Starink, Kissinger-Akahira-Sunose (KAS), and Ozawa-Flynn-Wall (OFW) methods, yielding values 235.985 kJ/mol, 235.918 kJ/mol, and 228.026 kJ/mol, respectively. The product exhibited highest activation energy 429.335 kJ/mol. The reaction rate increases exponentially as activation energy decreases. The isoconversional methods were used to predict activation energy of neem seedcake with coefficient of determination (R2) greater than 0.90. The reaction chemistry of NSC pyrolysis, characterized by high reactivity, was evidenced by thermodynamic parameters (entropy, enthalpy and gibbs free energy), which indicated increasing endothermic behavior as rate of conversion (α) increased from 0.20 to 0.75. The positive change in enthalpy (230.92 kJ/mol) throughout the process indicates, when neem seedcake decomposes, energy is absorbed (endothermic behavior) to break the complex chemical bonds. The neem seedcake pyrolysis promotes sustainable waste management, reduces pollution, decreases reliance on fossil fuels, and supports climate change efforts. This study enhances knowledge of biomass pyrolysis, especially for less-explored non-edible oil seedcakes.