This study examined the Impact of Instructional Supervision on Academic Performance of Secondary School Students in Nasarawa State with reference to Senior Secondary Certificate Examination (SSCE). Five research questions were used to guide the study to a rational conclusion. Descriptive Survey method was adopted in which Instructional Supervision and Students' Academic Performance Questionnaire (ISSAPQ) were used to obtain relevant data from 92 teachers in 37 selected Senior Secondary schools using the simple random sampling techniques. Pearson product moment correlational statistics (Pearson r) and t-test at 0.05 level of significance was used to analyse the data generated and answer the research questions. The study show that regular instructional supervision using robust supervision strategies like checking of students' notebooks, classroom visitation/inspection by school administrators, checking teachers' lesson plan/notes and inspection of teachers record keeping have significant correlation with teachers' performance and academic achievement of students in Secondary Schools. Recommendations like proper alignment of government policies with educational needs of the society, provision of adequate and relevant instructional materials for teaching, regular in-service training for teachers' capacity development, depoliticization of the free education programmes and proper evaluation of school administrative procedures and educational outcomes were adduced for remediation.