Background: Individuals with intellectual disabilities (IDs) face unique challenges in accessing cancer prevention measures. Caregivers play a crucial role in facilitating these measures, yet their perspectives are under-researched. Methods: This systematic literature review explores caregiver perspectives on cancer prevention for adults with IDs in institutional and home care settings, aiming to understand their roles, knowledge, and challenges. Thirteen articles from the UK, the USA, Canada, and Ireland were analyzed through thematic synthesis. Four overarching themes were identified: breast cancer screening perspectives, caregivers’ knowledge and barriers to cancer prevention, caregivers’ perspectives, and cultural context and decision-making. Results: Caregivers, including healthcare professionals and family members, are essential in facilitating breast cancer screening for individuals with IDs. Challenges include explaining screening procedures, limited awareness, and logistical barriers, highlighting the need for targeted educational interventions. Disparities in access underscore the necessity for comprehensive training programs. Healthcare professionals’ perspectives reveal existing disparities and suggest interventions for improved accessibility and understanding. Cultural context influences decision-making, emphasizing the importance of culturally sensitive care. The role of family caregivers in decision-making necessitates empowering and supporting them through tailored interventions. Conclusions: This review provides insights into the challenges and opportunities in cancer prevention for individuals with IDs, suggesting the need for educational interventions, training programs, and systemic changes to address disparities. It lays the groundwork for future research and the development of holistic and inclusive strategies in this critical healthcare domain.