The valorization of biomass and municipal solid wastes (MSW) based on their potential as alternative resource of energy is critical due to waste accumulation and dependence on nonrenewable fossil fuels. In this study, coconut husk (CH) and MSW under varying mixture compositions (85–95% CH and 5–15% MSW) were subjected to hydrothermal carbonization (HTC) at process parameters of 230 °C reaction temperature, 1 h holding time, 1:8 solids-to-water ratio, and 150 rpm stirrer speed. The production, fuel, physicochemical and mechanical properties of the produced hydrochar and its pellet were investigated. It was observed that the fuel properties from the parent materials were significantly improved based on higher heating value (>21 MJ/kg) and H/C and O/C ratios, comparable to that of sub-bituminous coal. The HHV of the hydrochar increased as CH composition increased, while its solids yield decreased simultaneously. Ultimate, proximate, and FTIR analyses confirm dehydration, deoxygenation, aromatization, and devolatilization of organic matter. Thermal stability investigation presents the decomposition of lignin which aided a positive binderless pelletization of the hydrochar. Morphological probing also shows increased hydrophobicity of hydrochar pellets. This investigation suggests a feasible pathway of mitigating waste and provides a technological route for alternative solid fuel production that can overcome challenges in handling and logistics.