This chapter explores the historical context and evolution of mental health care in prisons, noting the shift from deinstitutionalisation to the current reliance on correctional facilities as de facto mental health providers. It critically assesses the policies and practices that shape mental health support, including screening processes, the availability and quality of psychiatric care, and therapeutic interventions. The chapter also addresses the systemic barriers that impede effective mental health care, such as overcrowding, understaffing, and limited funding. Furthermore, the chapter explores innovative programmes and best practices that aim to improve mental health outcomes, such as integrated care models and re-entry programmes that provide continuity of care post-release. It concludes with recommendations for policy reforms and practical strategies to enhance mental health support, emphasising the need for a comprehensive, humane approach that prioritises the mental well-being of incarcerated individuals. This chapter provides a nuanced understanding of the complexities involved in delivering mental health care in jails and prisons and underscores the importance of addressing these issues to foster a more just and effective correctional system.