Mindfulness is defined as bringing one's attention to present-moment experience with acceptance, and is associated with engagement in various health behaviours. To synthesise and evaluate this literature, we conducted a comprehensive meta-analytic review and examined (a) the associations between trait mindfulness and health behaviours and (b) the extent to which these associations were moderated by study and individual differences. A total of 125 independent samples were included (N = 31,697, median male percentage = 38.8%, median age = 28.3). A multilevel random-effects model was used to estimate summary study-level effect sizes, and multilevel mixed-effects models were used to examine moderator effects. Mindfulness had a positive and small association with aggregated health behaviours (r = .08). Mindfulness was positively associated with physical activity, healthy eating, and sleep (rs = .08-.14), and negatively associated with alcohol use (r = -.06). Effects were larger for health promoting behaviours, the acting with awareness facet of mindfulness, and samples involving psychiatric patients. Although findings indicate that individual differences in trait mindfulness do not reliably translate into a pattern of healthful behaviours in general, trait mindfulness shows a stronger associations with health behaviours under certain conditions.