Objective: Individuals with eating disorders are known to have higher rates of insecure attachment compared to community controls, but the factors underlying this finding are poorly understood. We conducted the first meta-analysis comparing attachment in eating disorder samples compared to community controls that included quality assessment, publication bias and moderation analysis. Method: We pre-registered our meta-analysis (CRD42019146799) and followed PRISMA guidelines. We searched PsychINFO, Embase, Medline, CINAHL, and Scopus for publications. Attachment scores were extracted, and Cohen's d calculated for each study using a random effects model. Results: In total, 35 studies were included in the meta-analysis and six studies were summarized in a narrative review. Eating disorder samples showed higher rates of insecure attachment compared to community controls, with a large effect size, across measurement methods and different attachment dimensions. Blinding of assessors moderated effect sizes for attachment interview studies, but no other moderators were significant. Discussion: Risk of insecure attachment is elevated in individuals with eating disorders, albeit heterogeneity is high and largely unexplained. Clinicians may need to take this into account in their work, particularly given the association between attachment insecurity and challenges to therapeutic alliance. Future studies comparing eating disorder samples with community samples should control for general psychopathology. Public Significance: Attachment is a broad concept referring to a person's thoughts, feelings and behaviors in relation to close others. This systematic review and meta-analysis found that individuals with eating disorders are lower in attachment security than community controls, regardless of attachment construct or measurement approach. Attachment may be relevant in influencing eating disorder recovery, the development of therapeutic alliance, and potentially clinical outcomes, although more research is needed.