BACKGROUND AND OBJECTIVES: Given the stigma of dementia, individuals with the condition may be wary to disclose their diagnosis to other people, both in face-to-face and digital settings. While sharing one's dementia diagnosis with others is essential for accessing valuable support for social, cognitive, and physical well-being, this area of research has largely been neglected. In this meta-synthesis, we aimed to systematically review qualitative research on the factors associated with online and offline self-disclosure in people with dementia. RESEARCH DESIGN AND METHODS: We conducted a systematic search in 6 electronic databases. Inclusion criteria comprised qualitative and mixed-methods studies describing experiences with self-disclosure in people with any type of dementia. Quality of the included studies was assessed using the Mixed Methods Appraisal Tool. The meta-synthesis was conducted in NVivo using a thematic synthesis approach. RESULTS: 28 studies were included. 3 analytical themes were generated: "Concealment," "Stigma and fear," and "Taking control," the latter 2 with subthemes. Findings from this review were corroborated with people with dementia and family carers as part of Patient and Public Involvement meetings. Our findings reveal that while stigma plays a pivotal role, people with dementia can take control of the meaning of their diagnosis through self-disclosure. DISCUSSION AND IMPLICATIONS: Self-disclosure is complex and multifaceted. People with dementia, particularly those experiencing stigma, can benefit from post-diagnostic support that encompasses resources and interventions for self-disclosure. Further research is required to investigate people with dementia's disclosure decision-making process.