This research explores how technological, organizational, relational, and personality elements influence knowledge-sharing intentions and actions among academic personnel in higher education institutions. Grounded from social capital theory, social cognitive theory, and social exchange theory, the study aims to offer a thorough insight into the factors influencing knowledge-sharing intentions and the processes by which these intentions are converted into actions. Utilizing a quantitative, cross-sectional research design, data were gathered from 428 academic staff and students via a structured questionnaire and analysed using partial least squares structural equation modelling. The results show that the intention to share knowledge is notably affected by information technology, organizational support, trust, perceived mutual advantages, and reputation. Within these factors, trust and reputation stand out as indicators, underscoring the significance of relational dynamics in academic settings. Moreover, personality traits significantly influence as a moderating factor. In particular, an extroverted personality greatly enhances the connection between intention and behaviour, while an introverted personality does not adjust this relationship but rather directly impacts behaviour. These results enhance theory by showing that intention by itself cannot predict behaviour and by highlighting personality as an boundary condition. This study uniquely integrates structural, relational, and personality dimensions within a unified empirical model, extending existing knowledge-sharing research beyond intention-based explanations. The research suggests that postsecondary institutions should cultivate trust, enhance organizational support networks, and encourage mutual knowledge-sharing methods while developing inclusive atmospheres that cater to varying personality types in order to successfully narrow the intention–behaviour gap. Practically, the findings provide guidance for human resource and academic leaders in designating context-HR strategic sensitive policies and interventions that promote sustained knowledge-sharing behaviour.