The pervasive integration of artificial intelligence (AI) into societal systems—from workplaces to education—has ushered in an era where AI literacy is no longer optional but essential. This international study explores the self-perceived AI literacy, confidence, readiness and engagement of school librarians from over 50 countries (n = 319). Utilizing a mixed-methods exploratory design, the study combined quantitative survey data with qualitative insights to provide a comprehensive view of school librarians' AI preparedness. The findings revealed that while many participants rated themselves at an intermediate level of AI literacy, confidence and readiness to teach or integrate AI tools remained limited. Correlation analysis revealed significant associations between AI familiarity, literacy and confidence, highlighting the potential for professional development. Qualitative responses revealed four major barriers: institutional and policy limitations, educator mistrust and knowledge gaps, time constraints and lack of professional development, and student misuse coupled with ethical concerns. Based on these findings, an AI Leadership Framework is proposed to guide librarians in building critical and ethical AI competencies. The results underscore the need for targeted professional development and institutional support to empower school librarians as leaders in AI literacy, thereby preparing students for an AI-driven future.