This study was undertaken to design and develop an Online Library Management System (OLMS) to improve the efficiency of library operations. The system was developed to reduce operational errors, enhance record management, improve access to library resources and facilitate effective monitoring of library transactions. Specifically, the study examined the existing library management system, identified its limitations, designed a suitable library management solution, and developed a system for managing library activities. The study adopted the Waterfall Software Development Life Cycle (SDLC) model and Object-Oriented Methodology (OOM) for system analysis, design, and implementation. Data were collected through observation, consultation with library staff and users, and a review of relevant literature. System modelling tools, including use case diagrams, class diagrams, flowcharts, and entity relationship diagrams, were employed to capture requirements and guide system development. The system was implemented using PHP, HTML, CSS, JavaScript, and MySQL. The findings revealed that the existing manual library system was characterized by excessive paperwork, inefficient record management, delays in book lending and retrieval processes, difficulties in tracking borrowed materials, and a high likelihood of human error. The developed Online Library Management System automated key functions such as user registration, book cataloguing, borrowing and return transactions, and administrative monitoring. The system improved operational efficiency, enhanced record accuracy, and provided secure role-based access for users and administrators. The study concluded that the system provides a reliable, cost-effective, and user-friendly solution for library automation. It recommended the adoption of the system by academic libraries, regular data backup, enhanced security measures, user training, and future integration of mobile access, notification services, digital library features, and artificial intelligence-based recommendation capabilities.

Keywords: Online Library Management System, Library Automation, Object-Oriented Methodology, Waterfall Model, Academic Libraries, Database Management, Web-Based System.