This study investigated the influence of school supervision on the implementation of commerce curriculum in Senior Secondary Schools in Niger State, Nigeria. The researcher was motivated to embark on this study in view of the prevalent problems affecting effective implementation of commerce, ranging from lack of proper checking of the scheme of work and lesson notes in schools, irregularities of teachers in the classes, teachers? absenteeism, inadequate management of curriculum and instruction, lack of learner progress supervision by the instructional leaders. The problem also include low quality of student work and the quality of teaching and none organizing targeted opportunities for teachers to learn more about teaching strategies and methods. The study was conducted with five objectives in mind, which are to: assess the influence of school supervision on lesson plan preparation in commerce curriculum implementation, investigate the influence of school supervision on utilization of instructional methods in commerce curriculum implementation; determine the influence of school supervision on the use of instructional materials in the implementation of commerce curriculum; determine the influence of school supervision on teachers compliance with the keeping of continuous assessment records in commerce curriculum implementation; and identify the influence of school supervision on students keeping of workbook in commerce curriculum implementation process. Also, five corresponding research questions were raised while five null hypotheses were postulated. The study adopted descriptive survey research design. Out of the total of 50 instructional leaders, 2,342 female students and 1676 male students, a sample size of 10 inspectors, 10 Principals, 10 commerce teachers and 338 students offering commerce in Minna metropolis were used for the study. Data was collected through the use of a researcher designed questionnaire tagged Influence of school supervision on the implementation of commerce curriculum questionnaire (IOSSOTICCQ). The instrument was pilot tested and a reliability index of 0.86 was obtained. The analysis of the data collected was done using both descriptive and inferential statistics. The non-parametric statistic of Kruscal-Wallis was used to determine the presence or absence of significant influence for the five null hypotheses. All the null hypotheses were tested at 0.05 alpha level of significance. Findings revealed among others that supervision has positive influence on lesson plan preparation for teaching commerce in public Senior Secondary Schools in Niger State. Supervision had no significant influence on the utilization of instructional methods in commerce curriculum implementation in public secondary schools in Niger State. Supervision significantly influenced on the use of Instructional materials by teachers of commerce in public Secondary Schools in Niger State. Supervision encouraged and enhances influence on the extent to which teachers comply with keeping of continuous assessment records in public Secondary Schools in Niger State. Supervision had no significant influence on students keeping of workbook in commerce curriculum implementation process in public Secondary Schools in Niger State. Based on the findings from the study it was concluded that supervision had influence on lesson plan preparation, utilization of instructional methods and instructional materials in commerce in Senior Secondary Schools in Niger State. Recommendations were made among others that Principals and Inspectors should be given more necessary orientation which would guide them the more in their positions as instructional supervisors thereby promoting quality lesson plan in public Senior Secondary Schools in Niger State. Workshops, seminars and in service training should be organized for the teachers on the use of arrays of instructional methods for effective curriculum implementation