Background <p>People experiencing homelessness (PEH) face complex social and economic challenges that increase their risk of poor health. This study aimed to identify and synthesize key barriers to and facilitators of healthcare access from the perspective of PEH to inform more equitable and sustainable health strategies.</p> Methods <p>A systematic scoping review was conducted in accordance with the guidelines of the Cochrane Collaboration and the Joanna Briggs Institute and was reported following the Preferred Reporting Items for Scoping Reviews (PRISMA-ScR). A PubMed, Embase and Web of Science search was conducted in January 2025 using terms related to homelessness, healthcare, and interventional and observational studies. A manual search of the reference lists of the included studies was also performed via conventional search engines. Two reviewers independently classified the relevance of the extracted studies according to predefined eligibility criteria. Any discrepancies were solved by a third reviewer. The final list of studies enabled extraction of barriers to and facilitators of access to healthcare, subsequently classified according to the socioecological model.</p> Results <p>A total of 79 studies (<i>n</i> = 51,110 PEH) published between 1989 and 2024, mostly from the United States of America (USA) (<i>n</i> = 48; 63.3%), were included. Interventions most frequently addressed general healthcare (<i>n</i> = 25; 31.6%), treatment of specific conditions (<i>n</i> = 23; 29.1%) and sexual and reproductive healthcare (<i>n</i> = 7; 8.9%). Common individual-level barriers included health related-beliefs and concerns (<i>n</i> = 43), cognitive and behavioral health challenges (<i>n</i> = 28), and substance use (<i>n</i> = 18), whereas increased health awareness (<i>n</i> = 13) facilitated healthcare utilization. At the interpersonal level, social stigma (<i>n</i> = 51) and negative provider attitudes (<i>n</i> = 31) were prominent barriers, whereas strong social networks (<i>n</i> = 34) supported engagement. Institutional-level barriers included bureaucracy (<i>n</i> = 21) and lack of service integration (<i>n</i> = 20); conversely, continuity of care (<i>n</i> = 8) and process simplification (<i>n</i> = 7) acted as facilitators. Community-level barriers involved limited-service availability (<i>n</i> = 22), direct (<i>n</i> = 34) and indirect costs (<i>n</i> = 19); facilitators were centered on structure of the health service (<i>n</i> = 16). At the policy level, limited resources and service offer (<i>n</i> = 7), as well as undocumented situations by PEH (<i>n</i> = 4) were key barriers; strategically located services (<i>n</i> = 7) facilitated healthcare utilization.</p> Conclusion <p>Improving healthcare for PEH requires multilevel, person-centered strategies that address structural, interpersonal, and individual barriers while streamlining access through inclusive public policy.</p> Review registration <p>International Prospective Register of Systematic Reviews (PROSPERO): CRD42025635835.</p>