Computational analysis offers a cost-effective approach to exploring the doping concentration, device architecture, operating conditions, and material composition of perovskite solar cells (PSCs). A key aspect of computational research focuses on unravelling the electronic structure and optoelectronic behavior of perovskite materials. Density Functional Theory (DFT) calculations play a crucial role in determining energy levels, band structure, and density of states. Additionally, simulation-based modeling provides valuable insights into the influence of defects and interfaces on PSC performance, as factors like vacancies and impurities can significantly impact charge transport, recombination dynamics, and overall efficiency. With the rising popularity of multi-physics computational techniques, researchers can now analyze diverse electrical and thermal characteristics of PSCs in greater detail. This book presents a comprehensive exploration of advanced computational tools, including DFT, SCAPS-1D, and Multi-physics COMSOL, to examine critical properties such as optoelectronic behavior, electrical performance, band gap tuning strategies, doping effects, and defect densities. Notably, this edited volume introduces discussions on grading effects, multivalent defect analysis, scripting methodologies, and multi-terminal/multi-junction tandem configurations—topics integrated for the first time based on the latest research findings.