Social media's potential for knowledge dissemination is under-utilized due to limited user participation. This study systematically reviews factors affecting knowledge-sharing intentions on social platforms using the ROSES protocol. We searched Scopus and Web of Science for quality, relevance, and rigor, finding that 65% of the articles shared were published in high-quality journals (Q1 or Q2), with the Journal of Knowledge Management accounting for 15%. Since 2015, 62.5% of research has been published, highlighting increased activity. Quantitative methods dominated (95%), with Zhihu being the most studied platform. We identified four key themes-psychological, technological, environmental, and social-covering 47 determinants centered on trust and attitude, primarily based on individual and social behavior theories. This is the first systematic exploration of elements influencing knowledge-sharing intentions on social media, providing insights to enhance user interaction and guide social media strategies in knowledge-centric organizations.