Background: Individuals with intellectual disabilities (ID) typically exhibit cognitive deficits. While single bouts of physical activity (PA) have shown cognitive benefits in typically developing individuals, the effects on those with ID are unclear. This study aimed to investigate the effectiveness of single bouts of PA on cognition in individuals with ID. Method: This registered review followed the PRISMA guidelines and searched for eligible studies on PubMed and Scopus. Results: Eight studies were included, showing that participants demonstrated transient improvements in cognition, including information processing speed, inhibition and working memory, following moderate aerobic-based intensity PA. However, findings regarding the optimal intensity or types of PA for enhancing specific cognitions, and the effects on higher-level cognition (e.g., planning), are limited. Conclusions: Single bouts of PA may transiently enhance cognition in adolescents and young adults with mild to moderate ID, but more rigorous research with a feasible protocol is required to refine exercise prescriptions for maximal cognitive benefits.