Autism spectrum disorder and intellectual disability (ID) are linked to atypical sensory processing, but consensus lacks on the impact of their co-occurrence. We studied the impact of the presence of ID in autistic individuals on (1) sensory processing and (2) the relation between sensory processing and behavioral outcomes. A systematic review was performed on English-language peer-reviewed studies. Eleven papers were included. Papers based on overall and sensory subscales reported no impact of the presence of ID. Papers based on subtypes reported hyporesponsiveness and sensory seeking related to the presence of ID; hyporesponsiveness showed the poorest behavioral outcomes. Findings regarding the impact of the presence of ID are contradictory. More research regarding sensory subtypes is needed to investigate the needs of autistic individuals with ID.