The rapid shift to online learning during the COVID-19 pandemic has significantly influenced educational practices worldwide and increased the use of online learning platforms. This systematic review examines the impact of online learning on student engagement and performance, providing a comprehensive analysis of existing studies. Using the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guideline, a thorough literature search was conducted across different databases (PubMed, ScienceDirect, and JSTOR for articles published between 2019 and 2024. The review included peer-reviewed studies that assess student engagement and performance in online learning environments. After applying inclusion and exclusion criteria, 18 studies were selected for detailed analysis. The analysis revealed varied impacts of online learning on student performance and engagement. Some studies reported improved academic performance due to the flexibility and accessibility of online learning, enabling students to learn at their own pace. However, other studies highlighted challenges such as decreased engagement and isolation, and reduced interaction with instructors and peers. The effectiveness of online learning was found to be influenced by factors such as the quality of digital tools, good internet, and student motivation. Maintaining student engagement remains a challenge, effective strategies to improve student engagement such as interactive elements, like discussion forums and multimedia resources, alongside adequate instructor-student interactions, were critical in improving both engagement and performance.