This paper introduces systemic intelligence as a formal theoretical construct integrating systems thinking, system dynamics, and meta-awareness. It establishes seven foundational axioms and derives testable propositions for empirical investigation. It presents the Systemic Intelligence Scale (SIS), a 30-item measurement instrument operationalizing the three dimensions: perception (systems thinking), modeling (system dynamics understanding), and reflexivity (meta-awareness). The framework builds on second-order cybernetics, positioning meta-awareness as the reflexive variable that enables adaptive learning in complex systems. Applications span individual consciousness, organizational governance, and human-machine-world collaboration. The paper includes a comprehensive psychometric validation roadmap and discusses boundary conditions, competing frameworks, and practical implementation pathways. This work contributes to systems science, complexity theory, organizational learning, and AI ethics by providing both a theoretical foundation and empirical tools for cultivating intelligence capable of navigating interdependence and feedback in an age of accelerating complexity.