Perovskite solar cells (PSCs) have emerged as a prominent photovoltaic technology due to it’s high-power conversion efficiency, flexible material properties, and inexpensive production costs. However, maximising their efficiency and ensuring long-term stability require a thorough understanding of the interconnected physical processes at work. This chapter examines multi-physics phenomena in PSCs, including electrical charge transport, light absorption and optical behaviour, thermal management, and mechanical stability. The topic incorporates important modelling methodologies, including drift-diffusion models for charge dynamics, optical simulations for light control, and electro-thermal-mechanical coupling for device stability under real-world operating conditions. By merging these physical characteristics into unified multi-physics models, we may improve device performance, optimise material and device designs, and solve efficiency, degradation, and scalability issues. The chapter finishes with a discussion of developing trends in multi-physics simulations and their implications for the future development of PSC technologies.