Purpose of Review <p>Daytime sleepiness (DS) is a prevalent issue among students, potentially impacting their cognitive function and academic performance (AP). Thus, we performed this systematic review and meta-analysis (SR/MA) to investigate the relationship between DS and AP.</p> Recent Findings <p>A total of 54 studies were included in this study, and only 34 papers were used for the MA because the remaining papers did not provide effect size that can be converted to standardized mean difference (SMD). The MA showed that DS was significantly positively associated with poor AP with a SMD of 0.332; 95%CI: 0.182–0.483. However, subgroup MA presented that the effect size is more pronounced among non-college students (high school to middle school) with a SMD of 0.742; 95%CI: 0.428–1.056 compared with college students with a SMD of 0.096; 95%CI: 0.011–0.181. The certainty of the relationship between DS and AP was considered low (non-college students) and very low (college students) by GRADE assessment.</p> Summary <p>This study suggests that DS is associated with poor AP, particularly among non-college students. However, the certainty of the evidence was considered low. Thus, we recommended that future studies should control for the potential confounding variables such as physical activity, mental health, chronic health, socioeconomic, and study time/academic activity. Dose-response analysis should be performed to enhance the certainty of the evidence.</p>