ABSTRACTCoercion in mental health care is complex and controversial, often seen as a potential human rights violation. Coercion can manifest in various forms and is subject to ethical and legal judgement. Formal coercion includes measures restricting movement or providing treatment without consent. Informal coercion involves the use of communication and subtle interventions by mental health professionals to control, influence, manipulate or pressure patients, aiming to elicit specific behaviours and shape their decisions. Informal coercion often occurs in psychiatric care. However, it is not legislated; it is not discussed in clinical guidelines, and it is not formalised or documented. This scoping review aims to map the current understanding of informal coercion in inpatient psychiatry. Six databases were searched for studies examining definitions and conceptualisations of informal coercion. Data extraction included a summary and comparison of study characteristics, definitions and conceptualisations followed by thematic analysis using Braun and Clarke's approach. Twenty‐nine articles were included in the synthesis. The analysis led to the proposal of a definition of informal coercion and identified three key themes: first, the professionals' intentions, with attributes identified as patient protection or self‐protection; second, the methods used, including the attributes communication patterns, ‘legal’ coercion, deception, manipulation and abuse of power; and third, contextual factors leading to informal coercion, with attributes such as cultural adaptation, rule conformity and professionals' attitudes and skills. This study provides a conceptualisation for understanding informal coercion in inpatient psychiatry, highlighting its complexity and the need for ethical and professional reflection. Developing clear guidelines and standards is essential for protecting patient autonomy and dignity while enabling effective therapeutic interventions.Trail RegistrationThe research protocol was registered in the Open Science Framework (https://osf.io/ck3et).