This study investigated knowledge sharing behaviour of academic librarians as a predictor of information services delivery in public university libraries in South-East, Nigeria. It adopted a correlational research design, with a population of one hundred and sixty-eighty (168) academic librarians from six (6) public university libraries in South-East, Nigeria. The total enumeration sampling technique was adopted. Structured questionnaire was developed. The reliability coefficient of the instruments was established using Cronbach Alpha formula, which yielded 0.77 and 0.75 coefficient indices. Out of the 168 copies of the questionnaires distributed, 146 copies representing 87% response rate were completed and returned with valid information. The data collected were analysed using descriptive and inferential statistics. The study revealed that knowledge sharing behaviour of academic librarians for information services delivery in public university libraries manifests in the confidence of academic librarians in their ability and expertise to share knowledge via documents, reports, conferences; trust in their colleagues, supervisors and knowledge users, availability of relevant knowledge sharing policy backup, etc. It revealed that knowledge sharing behaviour of academic librarians impacts information services delivery by promoting professional development via learning of new skills; facilitating decision-making processes, improving collaboration with others, etc. The study found out that the major factors influencing knowledge sharing behaviour of academic librarians are individual motivation, organization culture, leadership support, technological factors and skills requirements. It concluded that knowledge sharing behaviour of academic librarians has a positive significant relationship with information services delivery in public university libraries in South-East Nigeria. The study recommended, among other measures that management of university libraries should create enabling environment, including provision of necessary resources and training for academic librarians in order to promote the desire and culture of knowledge sharing in public university libraries.