Over the last decades, interventions to support mental health and psychosocial well-being have become integral to humanitarian responses. This has resulted in a robust arsenal of methodologies and tools that are applied across multiple sectors, including health, protection, and education. Closely linked to this development is the emerging professionalization of the humanitarian workforce in relation to mental health and psychosocial support (MHPSS). It encompasses thousands of dedicated MHPSS professionals and an even larger number of humanitarian workers engaged through non-specialist roles. They are involved in a range of activities, including program design, service delivery, multisectoral coordination, as well as assessment, monitoring, evaluation, and learning. This chapter offers a concise overview of the scope of MHPSS concerns, outlines key conceptual frameworks and guidance documents for prioritizing and establishing programs, and introduces relevant intervention tools that can be used in humanitarian and displacement settings. It also reviews some of the critiques on mainstream MHPSS interventions in humanitarian interventions and discusses how the current humanitarian funding crisis could be used to make MHPSS interventions more integrated and locally driven.