To explore the association between leadership behaviours among managers in aged care, and person-centredness of care and the psychosocial climate.Theory suggests that leadership is important for improving person-centredness in aged care, however, empirical evidence is lacking.A cross-sectional design was used to collect data from Swedish aged care staff (n = 3661). Valid and reliable questionnaires assessing leadership behaviours, person-centeredness of care and the psychosocial climate were used. Data were analysed using multiple linear regression including interaction terms.Leadership behaviours were significantly related to the person-centredness of care and the psychosocial climate. The level of person-centredness of care moderated the impact of leadership on the psychosocial climate.The leadership behaviour of managers significantly impacts person-centred care practice and contributes to the psychosocial climate for both staff and residents in aged care. This study is the first empirically to confirm that middle managers have a central leadership role in developing and supporting person-centred care practice, thereby creating a positive psychosocial climate and high quality care.