The association between celiac disease (CD) and autism spectrum disorder (ASD) remains inconclusive. Reports from different observational studies have become controversial, necessitating exploration of the causal relationship between CD and ASD. To assess true causality, this study used a two-sample Mendelian randomization (MR) analysis to determine the causal association between CD and ASD. Summary-level data from a genome-wide association study (GWAS) of the European population were used to select instrument variables (IVs) at genome-wide significance (p < 5 × 10