<p>Ostracism (being ignored and excluded) thwarts basic psychological needs fundamental for human survival. As a painful experience, ostracism has various mental health, cognitive and behavioural consequences. In this Review, we outline the main psychosocial and behavioural consequences of ostracism and consider how these consequences might be unique within specific contexts, including workplace, school and online settings. Using a multiple-process framework, we integrate the existing theoretical models and original evidence to capture the mechanisms involved in the consequences of ostracism. Based on this framework, we elaborate on potential interventions targeting the underlying processes and focusing on individual and contextual moderators to reduce the detrimental effects of ostracism. We summarize challenges in the field and outline recommendations for future research.</p>