The aim of this review is to present the social media roles that facilitate knowledge management processes. This paper used a systematic literature review method based on PRISMA guidelines. The literature search was conducted using the following five electronic scientific databases: Web of Knowledge, Science Direct, Emerald, PubMed and Scopus. The search identified 82 selected works and the findings showed that social media facilitates knowledge acquisition by being used as a source of knowledge, facilitating knowledge accessibility and influencing knowledge creation and creating an interactive environment. Social media has created a new dimension of knowledge organisation by evolving knowledge storage, retrieval and classification activities. Social media has developed into a new flexible form of user’s communication by removing knowledge-sharing barriers, and accelerated knowledge sharing, in particular collaborative sharing. Finally, social media facilitates knowledge application activities such as knowledge translation, decision-making, education, problem-solving, team work and research process. The knowledge activities in social media need to be monitored for quality and reliability, and endangerment of ethics, users’ privacy, fake news, false information and negative comments need to be maintained.