This article contributes to territorial economics by examining how endogenous knowledge sharing fosters social innovation within an urban governance context, focusing on the city of Agadir. While social innovation has gained increasing prominence in development studies and public management research, the mechanisms through which territorial knowledge dynamics influence socially innovative practices remain insufficiently operationalized and empirically validated. In particular, there is a notable lack of standardized indicators capable of measuring the concrete impact of knowledge-sharing processes on territorial social innovation outcomes. This research addresses this gap by developing and testing an explanatory model that links territorial knowledge-sharing practices to social innovation among local stakeholders. Grounded in the theoretical intersection of knowledge management and social innovation studies, the research conceptualizes territorial knowledge sharing as a multidimensional process encompassing knowledge donating and knowledge collecting among actors embedded in a shared socio-spatial environment. Social innovation is operationalized through three interrelated dimensions: collective mobilization and management of territorial resources, socio-economic dynamism, and the remediation of social problems. By articulating these constructs within a coherent analytical framework, the study aims to determine whether territorial knowledge sharing constitutes a strategic lever for optimizing and promoting social innovation practices. Methodologically, the research adopts a deductive approach rooted in post-positivist epistemology. Hypotheses derived from theoretical postulates were empirically tested using Partial Least Squares Structural Equation Modeling (PLS-SEM). Data were collected through a structured questionnaire administered to actors directly involved in territorial governance in Agadir, including public institutions, economic organizations, cooperatives, and civil society entities. From 289 distributed questionnaires, 257 valid responses were retained for analysis. The empirical results confirm a strong and statistically significant positive relationship between territorial knowledge sharing and social innovation. These findings demonstrate that knowledge circulation mechanisms within a territory, when structured around reciprocity, collaboration, and active exchange, constitute a fundamental driver of socially innovative dynamics. The results further indicate that territorial innovation is not merely the outcome of isolated initiatives but rather the product of coordinated cognitive and relational processes embedded in the local ecosystem. Beyond statistical validation, the study highlights important governance implications. It underscores the need to broaden stakeholder participation and to integrate new actors into urban governance structures, reinforcing the conception of the city as a shared common good. Theoretically, this research advances the literature by providing an empirically validated, context-sensitive operationalization of territorial knowledge sharing and its contribution to social innovation within a North African urban setting. Methodologically, it illustrates the suitability of PLS-SEM for modeling complex socio-territorial dynamics in emerging governance contexts. Building on these findings, future research could extend the analysis through longitudinal and comparative designs in order to deepen understanding of the dynamic relationship between territorial knowledge sharing and social innovation. Expanding the scope to multiple urban contexts would enable richer cross-territorial insights and enhance the generalizability of the model. Further investigations may also integrate mediating and moderating mechanisms, such as absorptive capacity, inter-actor trust, or governance quality, to provide a more nuanced explanation of how knowledge-sharing processes evolve over time and contribute to sustained and scalable social innovation.