The educational landscape has been significantly influenced by the rapid development of technology, especially in the instructional process. Examining teachers’ professional digital competence (TPDC) in Indonesia, a developing country, is of utmost importance. It is vital to comprehend the extent of professional digital competence among teachers to identify potential gaps and areas for improvement through training programs. This investigation aims to shed light on disparities and formulate strategies to bridge the digital divide. In this context, the principal’s instructional e-supervision (PIS) and technology leadership (PTL) play a pivotal role in nurturing a school’s digital culture (SDC). This culture is crucial for ensuring the effectiveness of the collaborative learning process that meets the needs of students in this digital-savvy era. Therefore, this study delves into the structural impact of PIS and PTL on TPDC mediated by SDC. Quantitative methods were employed to address research hypotheses through structural equation modeling (SEM) analysis with AMOS, utilizing inner and outer model techniques. Carried out in seven senior high schools in Indonesia, the research involved 257 productive teachers randomly selected from a population of 450. The findings revealed that PIS directly influences TPDC, albeit with the most negligible coefficient (0.192). Simultaneously, PTL directly impacts SDC (0.663) and TPDC (0.229). Moreover, SDC significantly influences TPDC (0.816). However, the direct coefficient of PTL has a more substantial impact on SDC than on TPDC. Consequently, the structural model suggests that PTL will profoundly influence TPDC when mediated by SDC (0.541). In light of these results, this study recommends the application of principal technology leadership-based humbleness for future research.