Research indicates that individuals with intellectual disabilities (ID) are overrepresented among sexual offenders, and that those with ID might differ from those without ID in terms of the etiology of offending behavior. Despite this, few studies have explored ID using incarcerated U.S. samples. The present study sought to identify relevant characteristics of this population by comparing individuals with and without ID who are incarcerated in the U.S. for sexual offenses. Archival records for 3,066 participants were used to determine demographic, historical, and offense-related characteristics. Participants with ID, including those with borderline ID, comprised 19.1% of the sample and displayed elevated rates of adverse childhood experiences and psychopathology. Contrary to previous research, participants with ID were no more likely to offend against children than those without ID. These findings help to elucidate the etiology of offending behavior among those with ID and inform on potential targets for intervention.