There is a need to explore and comprehend the performance of sustainable leadership in enterprises’ circular economy-driven innovative activities. Firstly, there is a pressing necessity for businesses to remain agile and responsive to change, utilizing innovation not just as a buzzword but as a strategic tool for adaptation and growth. Secondly, the ethical dimension demands that innovation be pursued responsibly, considering its effects on communities, environments, and future generations. Lastly, the economic imperative underscores that sustainable innovation management can lead to efficiencies, cost savings, and new avenues for revenue generation. An improved comprehensive approach to evaluating the effectiveness of managing enterprises’ innovative activities is proposed. This approach is based on the evaluation of 14 partial indicators, each reflecting a specific vector orientation. This assessment allows for the combination of indicators that essentially reflect the personal characteristics of the manager and the combination of formative and resultant factors of the management’s influence on the state and results of innovative activity (the above-proposed factor approach). Consequently, it provides an opportunity to obtain a multifaceted, comprehensive, and most complete assessment of the sustainable management of innovative activity based on valid vector orientation within the scope of the subject and the object of research. Based on the proposed improved assessment, indicators of the effectiveness of managing innovative activities were calculated for the seven researched innovatively active industrial enterprises. Thus, the following were calculated: (1) the personal component (Pp) of the evaluation of the effectiveness of leadership in innovative activities using the expert assessment toolkit, (2) the managerial component (Plm), and (3) the innovatively sustainable component (Pis) of the evaluation of the effectiveness of sustainable management of innovative activities based on the internal reporting of the enterprise. This balances the partial subjectivity of the expert method with real data from specific enterprises. Consequently, based on the values of the three assessment components, a comprehensive integral indicator of the effectiveness of managing the innovative activity of the enterprise (Pef) was calculated. The proposed methodology’s validation proved its effectiveness and efficiency. The authors forecast the degree of influence of external and internal factors, taking into account the results of a comprehensive, integrated assessment of the effectiveness of sustainable management (Pef) on the economic development and indicators of the enterprise’s circular economy-driven innovative activities. This enables a significant strengthening of the resultant factors of managing innovative activities and predicting specific final results of all innovative activities.