Grounded in agency and stewardship theories, this study investigates the U‐shaped relationship between entrepreneurial orientation and exploratory/exploitative innovations and the moderating effects of strategic planning. Empirical data is collected from 396 A‐share listed public companies in China. Entrepreneurial orientation is assessed via internal R&D and external investment data, while content analysis captures exploitative, exploratory innovation, and strategic planning. The empirical findings yield two core conclusions: (1) This study finds the presence of U‐shaped relationships between entrepreneurial orientation and exploratory/exploitative innovations. As entrepreneurial orientation increases to an inflection point, it exhibits negative effects due to managerial agency behavior; however, beyond this point, it yields positive outcomes due to stewardship. (2) Strategic planning positively moderates the U‐shaped relationships, countering agency impact at low orientation levels while enhancing stewardship at higher levels. These insights advance entrepreneurial orientation research, agency vs. stewardship literature, and provide a roadmap for fostering exploratory and exploitative innovations through strategic integration of entrepreneurial orientation and leveraging of strategic planning.