The study concerned with the effect of Social Media on Academic Performance of Secondary School Students” with a specific focus on Ilobu Commercial Grammar School and Ima High School, Ilobu. There is no doubt about the fact that the world is completely in a global village as postulated by Professor Marshall McLuhan, according to him the world is now compressed into a single electronic room where information from far and near can be exchanged with a click of a mouse. The research is anchored on technological determinism theory and diffusion of innovation theory. A survey method was adopted with the use of a questionnaire to elicit data from the respondents. The respondents were drawn using multi-stage sampling technique. The data collected were analysed and interpreted using descriptive statistics (frequency and percentage). Findings show that social media enable people all over the world to engage in communication not only to share ideas and feelings but also to share it in interpersonal way irrespective of the location and time. They use social media to get in touch with some of their friends, including old friends to discover and establish new friendships. Despite the benefit, the majority of the social media lose their privacy and disclose the security and sensitive information to strangers online while many are now social media addicted, today many spend more than ten hours chatting and interacting with friends. It is recommended that social media users must ensure they understand why they are joining the social media site in the first place so that they would not be overcome by any negative impacts but rather they can use these sites for maximum benefit.