Municipal solid waste (MSW) torrefaction has gained attention as a promising thermochemical treatment that transforms heterogeneous urban waste into biochar with enhanced fuel properties and environmental benefits. This chapter reviews the fundamental mechanisms of MSW torrefaction and explores key process parameters influencing biochar quality, including temperature, residence time, and feedstock composition. Strategies such as co-torrefaction with biomass and the use of chemical additives are discussed for optimizing carbon content, energy density, and physical characteristics of the biochar. The chapter also presents a comparative analysis of reactor types suitable for MSW torrefaction and highlights the importance of energy and mass balance evaluations to improve process efficiency. Environmental considerations, including emission control and life cycle assessments, are addressed alongside techno-economic analyses that underscore the viability of torrefaction compared to other thermochemical processes. Overall, this work demonstrates the significant potential of MSW torrefaction to contribute to a circular economy by producing value-added biochar products while mitigating waste disposal challenges. Future research directions emphasize the need for interdisciplinary approaches to optimize technology deployment and market adoption.