AbstractThe energy sector plays a crucial role in facilitating the low‐carbon energy transition. However, in the absence of appropriate environmental regulation, managerial opportunistic behavior in energy firms can manipulate ethical investor perceptions and hinder the real transition process towards clean energy. Using Chinese listed energy firms as the research setting, this paper examines the impact of investor attention on energy firms' earnings management practices. In both clean and traditional energy firms, the results show a significant U‐shaped association between investor attention and earnings management, with the U‐shaped curve for clean energy firms being smoother. This U‐shaped relationship is more pronounced in energy firms with larger size and weaker external monitoring. Moreover, the mediating analysis shows that internal control quality transmits the impact of investor attention onto earnings management practices in the energy sector. Our key findings remain robust to a battery of robustness tests and endogeneity controls. Therefore, given the growing attention on the energy sector, this study extends the existing literature on energy firms' managerial opportunistic behavior by analyzing the nonlinear effect for investor attention and provides practical implications for curbing energy firms' managerial opportunistic activities and guiding managerial attention towards making real sustainable investments, thereby promoting clean energy transition and sustainable development.