<![CDATA[Mental health has become an increasingly important concern in modern society, yet research examining the relationship between spatial design and psychological well-being remains fragmented across the fields of psychology, architecture, and environmental health. Existing studies often focus on individual design elements, such as natural lighting, privacy, or biophilic features, without providing a comprehensive understanding of how these components collectively influence psychological well-being. Therefore, this study aims to systematically examine the relationship between spatial design and Psychological Well-Being (PWB) from the perspective of architectural psychology and identify environmental factors that most consistently contribute to mental well-being. This research employed a Systematic Literature Review (SLR) using the PRISMA framework. Relevant articles were retrieved from Google Scholar, Scopus, and ScienceDirect through Publish or Perish software and selected based on predetermined inclusion and exclusion criteria. Five studies published between 2020 and 2026 were included in the review. Data were analyzed using thematic analysis and narrative synthesis to identify recurring patterns and themes across studies. The findings indicate that spatial design significantly influences psychological well-being through factors such as biophilic design, nature connectedness, privacy, spatial organization, and multisensory environmental experiences. Environments that incorporate natural elements are associated with reduced stress, improved mood, enhanced emotional regulation, and higher levels of well-being. Furthermore, built environments that support autonomy, competence, and social connectedness contribute positively to psychological functioning and overall quality of life. This study provides an integrated understanding of how environmental design affects psychological well-being and offers evidence-based insights for architects, interior designers, and policymakers in creating restorative and mentally supportive environments.]]>
