Leading a school during the uncertainties of challenges, changes, and crises requires school principals to respond and react effectively, cohesively and proactively using resilience. Rather than using discrete contracts or dimensions to measure principal resilience, this paper tended to develop and validate a multidimensional instrument of principal resilience. Derived from the existing literature and three empirical studies, a 20-item Principal Resilience Inventory has been established by using a rational-theoretical approach of test construction with various samples of school principals from Hong Kong and Mainland China. The Principal Resilience Inventory encompasses five dimensions that capture the most salient resilience experience of school principals including physical, emotional, psychological, cognitive, and social resilience. Given a robust validation procedure, this instrument offers solid proof of the psychometric properties. It is expected that this validated measure can serve as a more robust means for gauging comprehensive investigations of principal resilience. Indeed, principal resilience is not just a buzzword, but an important quality that supports principals to infuse themselves into their professional lives in pursuit of the collective good.