The study investigated effective leadership styles strategies and job performance of librarians in Federal University libraries in South-South, Nigeria. The study adopted descriptive research design. A total of four (4) research questions were raised to guide the study, and a hypothesis was also tested at 0.5 level of significant. The population of the study comprised (98) librarians in the six Federal universities spread across the six states of South-South, Nigeria. No sample was done due to the manageable size of the population. The instrument used for data collection was a researcher constructed questionnaire titled “Effective Leadership Styles Strategies and Job Performance Questionnaire (ELSSJLSQ)”. Various types of leadership styles were identified, challenges associated with leadership styles and job performance were also identified to include lack of proper education on human resource management, lack of knowledge on the type of leadership style to be adopted, and inability to engage staff in task performance etc. The study outlined strategies for effective leadership style for increased job performance, to include participatory management approach, disciplinary measures for bad performance, regular staff training programmes among others. Based on the findings, recommendations were made.