This paper examines the quantitative relationship between knowledge management and technological innovation and their influence on sustainable development. Organizations have increasingly focused on knowledge management processes, recognizing their importance for maintaining competitiveness and sustainability. The purpose of our study was to shed light on the impact of knowledge management processes on a firm’s sustainability and innovation. Specifically, we investigated the relationship between knowledge acquisition, knowledge storage, knowledge transfer, and knowledge application and their effects on product/service innovation, process innovation, radical innovation, and incremental innovation. Using data from 272 questionnaires completed by top managers from companies operating in Greece, we provide strong evidence of a positive relationship between knowledge acquisition, storage, and application on product innovation whereas knowledge acquisition, storage, and transfer have a statistically significant effect on process innovation. Furthermore, we found a strong positive relationship between knowledge transfer and radical innovation. Finally, all four knowledge management processes have a strong positive impact on incremental innovation. The strength of these statistically significant results is reinforced by the magnitude of the corresponding estimated coefficients. The robustness of our results was further confirmed through the estimation of a Structural Equation Model (SEM) with the application of the Partial Least Squares (PLS) technique.