We explored the relationships among university student's gender, online learning engagement, attitudes toward online learning, readiness, and academic achievement in a public university. While previous research highlights the importance of these factors in online learning, their combined effects remain underexplored, particularly in the Nigerian context. We employed a quantitative research design, collecting data from 353 students through a structured questionnaire. Descriptive statistics, correlation analysis, and multiple regression were used for data analysis. Our results reveal that students exhibit high engagement, readiness, and positive attitudes toward online learning. However, none of these factors significantly predicted academic achievement, suggesting that success in online learning may depend on other elements, such as instructional quality and technological infrastructure. Gender also showed no significant impact on performance. We emphasize the need for a holistic approach to online education, focusing on systemic improvements in teaching practices, course design, and support systems to enhance student success.