Equanimity is an important concept in the relationship between Buddhist tradition and contemporary mental healthcare. In both practices, equanimity matters deeply, so it represents a useful point of interaction between Buddhism and psychiatry. In the history of medicine, equanimity has been emphasised by such figures as Irish asylum doctor James Duncan (1812–1895) and Canadian physician Sir William Osler (1849–1919). Recent decades have seen a remarkable growth in literature linking various aspects of Buddhism with psychiatric care, as well as cross-cultural conceptualisations of equanimity and emotional equilibrium. Links with Buddhist thought include the ‘Four Immeasurables’ or brahmavihārā of Buddhist tradition, which are loving-kindness (mettā), compassion (karuṇā), empathetic joy (muditā), and equanimity (upekkhā). This chapter discusses the resonances between Buddhism and psychiatry in this context, along with the limits of equanimity and the need for other values to complement it. The chapter concludes by presenting evidence of the benefits of cultivating equanimity in the general population and among health professionals, along with practical ways to deepen equanimity, especially in psychiatry but also more broadly. These approaches focus on five key themes: (a) emotional awareness; (b) mindfulness; (c) reflective practices; (d) self-compassion and self-care; (e) anchoring in professional purpose.