Smartphone addiction could be described as smartphone mismanagement, mishandling and misuse. It is also being fuelled by the fear of being without a mobile phone for certain number of hours. It is a non-chemical addiction that is been driven by an Internet overuse problem thereby becoming a destructive behaviour. Smartphone addiction has the capacity to negatively affect an individual in his/her physical and mental health, relationships, productivity and academic performance. This paper therefore, examined impacts of Smartphone addiction on academic performance of students in senior secondary schools in Lagos state. One research question and three hypotheses were formulated to guide the research. The sample consisted of one hundred and thirty (130) students randomly selected from four senior secondary schools in Lagos state. A 25-item questionnaire designed by the researchers titled “Addiction to Smartphone Inventory” (ASPI) was designed for data collection. Cronbach’s Alpha reliability coefficient of the instrument stood at 0.91. The study adopted the descriptive survey design to seek information. Data analysis was carried out with the use of percentages, t-test and ANOVA. Results showed that there is a significant impact of Smartphone addiction on academic performance of students in senior secondary schools in Lagos state. The results also revealed that academic performance of students is not gender based, neither does it depended on the type of school. Students in senior secondary schools should be exposed to dangers inherent in smartphone addiction and how they can overcome the menace.
