Although third-wave behaviour therapies are being increasingly used for the treatment of eating disorders, their efficacy is largely unknown. This systematic review and meta-analysis aimed to examine the empirical status of these therapies. Twenty-seven studies met full inclusion criteria. Only 13 randomized controlled trials (RCT) were identified, most on binge eating disorder (BED). Pooled within- (pre-post change) and between-groups effect sizes were calculated for the meta-analysis. Large pre-post symptom improvements were observed for all third-wave treatments, including dialectical behaviour therapy (DBT), schema therapy (ST), acceptance and commitment therapy (ACT), mindfulness-based interventions (MBI), and compassion-focused therapy (CFT). Third-wave therapies were not superior to active comparisons generally, or to cognitive-behaviour therapy (CBT) in RCTs. Based on our qualitative synthesis, none of the third-wave therapies meet established criteria for an empirically supported treatment for particular eating disorder subgroups. Until further RCTs demonstrate the efficacy of third-wave therapies for particular eating disorder subgroups, the available data suggest that CBT should retain its status as the recommended treatment approach for bulimia nervosa (BN) and BED, and the front running treatment for anorexia nervosa (AN) in adults, with interpersonal psychotherapy (IPT) considered a strong empirically-supported alternative.