The purpose of this article is to explore the development of the knowledge base on middle leadership in schools. Since the seminal reviews conducted by Bennett a contemporary scan only of the scholarly literature on middle leaders/leadership in schools has not been undertaken. Consequently, this article looks at outputs relating to this topic by examining research papers indexed in the Web of Science and in SCOPUS between 2003 and 2017. The prime purpose of this review is to offer some reflections on the development of the empirical base on middle leadership in schools since 2003 and to highlight some of the implications for future research. The article concludes that middle leadership in schools remains an ongoing focus of research inquiry in a growing number of countries but suggests that the knowledge base would benefit from more sophisticated empirical studies and greater theoretical analysis.