Background: People with intellectual disabilities face inequities in access to end-of-life care and inequalities in its quality and delivery. This review aimed to synthesise qualitative evidence to understand their own perspectives about what contributes to optimal end-of-life care. Methodology: Data from 93 participants in five qualitative studies were thematically synthesised to identify optimal care and inform recommendations. Results: Four overarching and interrelated analytical themes were generated. (1) Optimal care recognises heterogeneity and is person-centred. It aligns with individuals' wishes and preferences which are established through 'active' communication. (2) This enables an individual's holistic support needs to be identified. (3) It fulfils ethical obligations around autonomy, equity and a person's 'right to know'. (4) It involves the necessary people to ensure all needs are met. Conclusion: Optimal end-of-life care is person-centred, holistic, uses 'active' communication, meets ethical obligations and involves the necessary people in care.