Background: People with intellectual disabilities are more likely to be prescribed psychotropic medication than the general population and are frequently prescribed multiple medications. Understanding people with intellectual disabilities and carer perspectives is essential to improving the quality of psychotropic medication prescribing and usage. Method: A rapid review explored people with intellectual disabilities' understanding of psychotropic medications, as well as family members and paid carers, and how this understanding can be improved. Results: Twenty-one journal articles were included. Lack of understanding of medication was universal, with participants often unaware of adverse effects, alternatives, and rights around medication. There was also a lack of involvement in decision making for all participants. Some interventions aimed at people with intellectual disabilities or paid carers helped to improve knowledge. Conclusion: Evaluating how best to improve psychotropic medication understanding for people with intellectual disabilities, family members and paid carers should be a focus for future research.