The number of older adults identifying as lesbian, gay, bisexual, transgender and other sexual and gender diverse identities (LGBTQIA+) is growing as populations age and social environments become more accepting. This study uses a global evidence synthesis to understand perceived barriers and facilitators to access to sexual healthcare globally for older LGBTQIA+ adults. We used a scoping review and qualitative evidence synthesis. Embase, PubMed and PsycInfo were searched with terms related to LGBTQIA+ populations, adults aged 45years, and sexual health care. We used the Cochrane Handbook and the review protocol was registered. Primary and secondary textual data were coded and grouped into themes using PRISMA-SCR and the Minority Stress Model. The certainty of review findings was assessed using the GRADE-CERQual approach. We identified 19 studies and 15 were included in the qualitative evidence synthesis. All studies were from high-income countries. Heterocentricity and male-centricity of sexual healthcare services contributed to feelings of exclusion for older LGBTQIA+ adults. Both anticipated and enacted stigma from healthcare providers resulted in older LGBTQIA+ adults, especially those with chronic conditions, avoiding health services (seven studies each, low certainty). Older LGBTQIA+ adults have unique sexual health needs and may feel their age empowers them to access appropriate care (four studies, low certainty). This review highlights the need for additional research and interventions to improve sexual health services for older LGBTQIA+ adults. Practical strategies to make sexual health less heterocentric (e.g. gender neutral signage) may increase uptake of essential sexual health services.