<p>This study presents a systematic literature review on the assessment of vulnerability and climate change adaptation in coastal cities and communities worldwide, with an emphasis on the use of participatory methodologies. The bibliographic search was conducted in the Web of Science database using structured keyword blocks, and the screening of studies was supported by a supervised machine learning algorithm (XGBoost), trained on a manually reviewed sample to optimize the identification of relevant articles. A total of 4,486 articles published between 1955 and September 2025 were analyzed, showing a sharp increase after the 2000s and a predominance of case studies in Asia. Although the literature has evolved from predominantly physical and single-hazard assessments toward more integrated approaches incorporating socio-ecological dimensions, governance, and adaptive capacity, the effective inclusion of social participation remains limited. Only 48 studies explicitly incorporated participatory approaches, indicating that community engagement is not yet systematic. This gap is even more evident in South and Central America and Africa, where case studies are fewer, participatory approaches are scarce, and limitations in data availability and monitoring infrastructure persist. Adaptation, vulnerability, exposure, and impacts were the most frequent themes, while mitigation remained significantly less explored, and storms, sea-level rise, and coastal erosion were the most frequently addressed hazards. The review highlights that strengthening climate adaptation in coastal cities requires not only better data and integrated assessment methods, but also the systematic expansion of participatory approaches that effectively engage local communities, support local decision-making, and reduce regional inequalities in climate adaptation research.</p>