A social media site is an internet platform that facilitates 24-hour communication/interaction around the globe. This media usage cuts across all ages including the older generation but it is predominately used by the youth. This study was conducted to inquire about the use of social media sites and their effects on selected secondary school students in Akure South Local Government Area, Ondo State. A descriptive survey was adopted for this study and a questionnaire was the instrument used in gathering the data. A total of four hundred and eighty (480) questionnaires were distributed and four hundred and seventy-four were retrieved and analyzed using frequency and percentage in presenting the results. The study revealed that Facebook, WhatsApp, and 2go were the most commonly used social media sites by the secondary school students under study, 231(48.7%) of the students visit these social media sites daily, 155(32.7%) agreed to the fact that they find it difficult to concentrate on their studies due to the use of social media. The study concluded that the negative sides of social media on secondary school students are of a greater proportion compared to its positive sides. The study recommends that there should be regular Orientation for students in secondary schools on the effective use of social media for academic purposes. School counselors need to step up their games in guiding the students on the use of social media among the youths.