This study aimed at examining the usage of social media platforms used on learning and library services in Higher Learning Institutions in Zanzibar. The Study specifically focused on five (5) social media platforms at three selected universities located in Zanzibar. The study involved three research questions. The first question was saying about what are the types of social media platforms used on learning and library services for knowledge sharing in SUZA, ZU, and SUMAIT? The second question said what are the uses of social media platforms used on learning and library services for knowledge sharing in SUZA, ZU, and SUMAIT? And the third question said that what are the challenges facing librarians when social media platforms are used on library services for knowledge sharing in SUZA, ZU, and SUMAIT? The methods that were used in the study include both quantitative and qualitative research designs. Questionnaires and interview tools were used for collecting data to the respondents. The combinations of purposive and stratified random sampling techniques were employed on library users through questionnaires and interviews would take with librarians. The result of this study showed that social media platforms are very well known by the respondents and daily used in their studies. Also, social media are effectively used in most academic libraries to support education progress and most of the respondents prefer using social media in their studies because of Sharing knowledge that involves learning, understanding, extending, and repeating the information, ideas, views, and the resources among persons, connected on a specific ground. The result presented that the availability of social media platforms in the academic library has totally changed the image of the library in terms of delivering the services to the users from the librarians who use social media for reference purposes as a result of having a high number of users on using library through knowledge sharing. The result of the study showed that Poor knowledge of managing and using electronic records and Poor support from the management are the great challenges facing libraries in operating social media platforms on learning and library services for knowledge sharing in higher institutions in Zanzibar as a result of failing to reach many audiences. The study concluded that Social media provide more chances for interaction, connection, sharing, and communication with library users in the library. Librarians could use social media to market their services and resources using different platforms.