Background: Acceptability of healthcare is gaining ground in public health research and practice. Overlooking healthcare acceptability when designing, implementing, monitoring and assessing healthcare interventions may lead to those interventions failing. Despite the importance of acceptability, the public health community still has to agree on an explicit definition and conceptual framework of acceptability. We considered different definitions and conceptual frameworks of healthcare acceptability, and identified commonalities to develop an integrated definition of healthcare acceptability. Methods: We conducted a synthesis review and thematic content analysis of research articles that attempt to define healthcare acceptability. We searched online databases including MEDLINE/PubMed, Cochrane Library and Google Scholar for relevant articles. The retained articles were imported into ATLAS.ti 8.4. Using thematic content analysis, we deductively and inductively coded categories and themes related to definitions and frameworks of healthcare acceptability. Results: Our review of the literature described the complexity of healthcare acceptability. The concept of acceptability remains poorly defined limiting its application in public health. We propose a definition of acceptability that includes the needs and expectations of the healthcare recipient, healthcare provider as well as the capacity of the healthcare systems. We define acceptability as a multi-construct concept describing nonlinear cumulative combination in parts or in whole of expected and experienced degree of healthcare from patient, provider or health systems and policy perspectives in a given context. We provide a conceptual framework of acceptability, applicable to the public health research and practice. Conclusion: We present a definition of acceptability that can be applied to different actors of public health including patients, providers, and health systems or policy. The proposed definition of acceptability, together with the conceptual framework provides a coherent conceptualisation that can be used by the broader public health community.