The main aim of this examination is to examine the impacts of school discipline management on students’ academic performances under Uganda’s private secondary schools within Jinja City. The following specific goals guided the examination; i) To examine the impact of enforcement of school rules on students’ academic performance, ii) To examine the influence of counseling and guidance on students’ academic performance, and iii) To examine the impact of punishment on students’ academic performance in private secondary schools in Jinja City, Uganda. The examination embraced a research design for cross-section focused on a quantitative technique. Regression analysis for simple linear was used to determine how well school discipline management predicts students’ academic performance at a given significance level. The study revealed that enforcement of school rules possesses a statistically constructive and substantial effect upon students’ academic performances within private secondary educational institutions within Jinja City, Uganda (β=.385, P-value<.05). The study also revealed that counseling and guidance possesses a statistical constructive and substantial impact on students’ academic performances in Uganda’s private secondary educational institutions within Jinja City (β=.574, P-value<.05). Further, the study revealed that punishment possesses a statistical weak constructive but substantial impact on students’ academic performances under private secondary educational institutions in Jinja City, Uganda (β=.364, P-value<.05). This  investigation concludes that school discipline administration through enforcement of school regulation, counseling and enlightenment, plus punishment has a considerable impact on learners’ academic performances within private secondary educational institutions within Jinja City, Uganda whereby an improvement in the various dimensions of school discipline management would significantly result into an enhamcement within students’ academic performances under Uganda’s private secondary educational institutions within Jinja City. This study commends that schools should develop clear behavioral expectations that are apprehended by parents , teachers, and students, besides should be clearly communicated as well as applied consistently and fairly to all students as this would reduce confusion and help students focus on learning, improving students’ academic performances under Uganda’s private secondary educational institutions within Jinja City.