The biogas-to-hydrogen process produces hydrogen through the reforming of methane gas generated through anaerobic digestion of organic waste materials, and there are unit processes that use a lot of electricity, such as gas compression in the process requiring further reduction of the electric energy used in the process itself or generation of additional power by utilizing waste heat. In this study, three waste heat sources in the biogas-to-hydrogen process were assigned, and an organic Rankine cycle (ORC) was installed to maximize the power production by optimizing the system pressure and the amount of working fluid sent to each waste heat source. The simulation study and techno-economic analysis showed that 30 bar was determined to be the optimal system pressure when installing an ORC system using R600a as the working fluid, and the optimal distribution ratio of the working fluid to the three waste heat sources was 36.9:37.2:25.9, which resulted in the highest system efficiency of 15.2%. The economic feasibility of the ORC was also demonstrated with a payback period of 5.5 years when applying these optimal operating conditions at a 3 MT/h biogas processing scale.