Mindfulness can be measured as an individual trait, which varies between individuals. In recent years, research has investigated the overlap between trait mindfulness and attachment. The aim of the present review and meta-analysis was to investigate the current evidence linking adult attachment dimensions to trait mindfulness dimensions, and to quantitatively synthesize these findings using meta-analyses. A systematic literature search was conducted using five scientific databases of which, upon review, 33 articles met inclusion criteria. Inclusion criteria were peer-reviewed journals and dissertations published in English that relied on quantitative methods using reliable and validated self-report measures where study participants were aged 16 years and older. Random-effects model meta-analytic procedures were used to investigate the relationship between both constructs. Cross-sectional studies found significant negative correlations between adult attachment insecurity, on either dimension (anxiety or avoidance) and both total mindfulness score and all five sub-dimensions of mindfulness (act with awareness, observe, describe, non-reacting, and non-judging), with the exception of a non-significant positive correlation between attachment anxiety and observe. The effect size of the relationships ranged from small to medium. The overall mean effect sizes were moderate (anxiety, r+ = .34; avoidance, r+ = -.28), with both attachment dimensions associated with lower levels of total mindfulness. Results are discussed in relation to theory and research. Implications for future research include the need to utilize longitudinal design to address causality and mechanisms of the relationship between these constructs.