Abstarct: The present study aimed to investigate the effect of digital transformation on firm performance through the mediating roles of cloud-baxsed accounting effectiveness and decision-making quality, as well as the moderating role of digital leadership. This research was applied in terms of purpose and employed a descxriptive-survey and correlational design. The statistical population consisted of financial managers, information technology managers, and senior managers of knowledge-baxsed firms located in Pardis Technology Park, Tehran, that use cloud-baxsed accounting systems and digital technologies. A total of 92 eligible firms were selected, and three managers from each firm participated in the study, resulting in a final sample of 276 respondents. Data were collected using a 36-item questionnaire and analyzed through partial least squares structural equation modeling (PLS-SEM) using SmartPLS software. The findings revealed that digital transformation had a positive and significant effect on both cloud-baxsed accounting effectiveness and firm performance. Cloud-baxsed accounting effectiveness significantly improved decision-making quality, while decision-making quality, in turn, positively enhanced firm performance. Furthermore, cloud-baxsed accounting effectiveness significantly mediated the relationship between digital transformation and decision-making quality, and decision-making quality mediated the relationship between cloud-baxsed accounting effectiveness and firm performance. The results also confirmed the positive moderating role of digital leadership in the relationship between digital transformation and cloud-baxsed accounting effectiveness, as well as in the relationship between cloud-baxsed accounting effectiveness and decision-making quality. Overall, the findings indicate that the simultaneous development of digital transformation, effective cloud-baxsed accounting, data-driven decision-making, and digital leadership can contribute significantly to improving the performance of knowledge-baxsed firms.