The 11th revision of the World Health Organization's International Classification of Diseases (ICD-11) proposed two sibling diagnoses, namely post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD). We aimed to synthesize studies that evaluated the association between adverse childhood experiences (ACEs) and PTSD or CPTSD. Systematic search of 7 databases identified 24 studies (282 effect sizes; 17,075 participants). Separate three-level random effects meta-analyses were conducted to examine the associations between ACEs and the ratio of PTSD to no diagnosis, CPTSD to no diagnosis, and CPTSD to PTSD. Moderator analyses were conducted with different types, numbers, dimensions, causes, intentions, locations, victims of ACEs, and the co-occurrence of different causes and locations of ACEs. ACEs contributed to higher ratios of PTSD (OR, 1.56; 95% CI, 1.38-1.77) and CPTSD (OR, 2.59; 95% CI, 1.86-3.61) compared to no diagnosis and a higher ratio of CPTSD to PTSD (OR, 1.70; 95% CI, 1.24-2.34). Physical, sexual, and emotional abuse, household dysfunction, and broader composite measures of ACEs characterized increased risks for PTSD and CPTSD. The association between ACEs and PTSD was moderated by the type and intention of ACEs. The association between ACEs and CPTSD was moderated by type, number, location, and the co-occurrence of different causes and locations of ACEs. The association between ACEs and the ratio of CPTSD to PTSD was moderated by type and the co-occurrence of different causes and locations of ACEs. These findings highlight that ACEs distinguish risk for PTSD and CPTSD.