Cleaning validation remains a cornerstone of pharmaceutical quality assurance, ensuring that manufacturing equipment is consistently cleaned to predetermined acceptance criteria that protect patient safety and product quality. The pharmaceutical industry has witnessed a significant paradigm shift from traditional compliance-based approaches toward science-based, risk-based methodologies for cleaning validation. This paper provides a comprehensive review of risk-based cleaning validation, examining the regulatory framework established by ICH Q9 and related guidelines, the evolution of acceptance criteria from arbitrary limits to health-based exposure limits, and the application of quality risk management tools such as Failure Mode and Effects Analysis. The lifecycle approach to cleaning validation, sampling methodologies, and strategies for preventing cross-contamination in multi-product facilities are discussed. This review synthesizes current literature and regulatory expectations to provide pharmaceutical professionals with practical guidance for implementing robust, scientifically justified cleaning validation programs.