<p>While the literature on inter-firm knowledge sharing has received increasing research attention, there is a scarcity of research on intra-firm knowledge sharing and application, and to establish its implications which we argue are critical to improving the operational outcomes of firms. Our study draws insights from the collective intelligence theory to investigate the relationships between intra-firm tacit KS, intra-firm explicit KS, and intra-firm knowledge application on informal SMEs of a developing economy. We also investigate the mediating role of innovation capability on the relationship between these dimensions of knowledge and the firms’ operational performance. We adopted the PLS-SEM to analyze data drawn from 371 owners and owner-managers of SMEs in Nigeria’s largest electronic informal market, namely Alaba International Market. The results reflected that intra-firm tacit KS and intra-firm explicit KS positively relate to operational performance. Similarly, the application of intra-firm knowledge application relates positively to innovation capability. We also found that innovation capability mediates the respective relationships between intra-firm tacit KS, intra-firm explicit KS, intra-firm knowledge application, and operational performance. Our study advances the theoretical and practical landscape of knowledge management (KM), and innovation capability by offering new insights into the deployment of intra-firm knowledge sharing to support the operational areas of SMEs that are confronted with the challenge of limited access to resources.</p>