School middle leadership is a complex and increasingly important school leadership position, with research showing the significance of middle leadership to school improvement and teacher development. The purpose of this article is to identify and analyse empirical peer reviewed articles on middle leadership from 2006 to 2020, to understand how middle leaders are defined, the responsibilities they hold, the impact and professional development they are afforded, and to discover lacunae in studies to support further research. The review was conducted using Scopus and ERIC; a total of 35 articles across 14 countries were selected. Using Nvivo, narrative synthesis was utilised to analyse the articles resulting in four conclusions: 1) middle leadership is difficult to define; 2) middle leadership positions and responsibilities vary considerably and are best understood in context; 3) middle leaders directly and indirectly impact teacher practice, team development, school reform and professional learning, although there is limited direct research into their impact; and 4) middle leadership professional learning has not progressed to the point to adequately equip middle leaders for the complexity of their positions. The article highlights two distinguishable differences to separate teachers and middle leaders, and provides an operational definition, elaborated description and set of middle leadership characteristics to guide future research and policy advancement.

学校的中层领导者是一个复杂且日益重要的学校领导职位，研究表明中层领导者对学校改善和教师发展具有重要意义。本文的目的是确定并分析有关2006年至2020年间中层领导的经验性同行评议文章，以了解中层领导的定义，他们所承担的责任，所提供的影响和专业发展以及发现研究中的缺陷支持进一步的研究。审查是使用Scopus和ERIC进行的；共有14个国家/地区的35篇文章入选。使用Nvivo，叙事综合被用来分析文章，从而得出四个结论：1）中层领导者很难定义；2）中层领导职务和职责相差很大，应根据具体情况予以最佳理解；3）中层领导者直接和间接地影响教师的实践，团队发展，学校改革和专业学习，尽管对其影响的直接研究有限；（4）中层领导者的专业学习尚未发展到足以使中层领导者的职位复杂化的程度。本文强调了区分教师和中层领导者的两个明显区别，并提供了操作定义，详尽的描述和中层领导者特征集，以指导未来的研究和政策发展。尽管对其影响的直接研究有限；（4）中层领导者的专业学习尚未发展到足以使中层领导者的职位复杂化的程度。本文强调了区分教师和中层领导者的两个明显区别，并提供了操作定义，详尽的描述和中层领导者特征集，以指导未来的研究和政策发展。尽管对其影响的直接研究有限；（4）中层领导者的专业学习尚未发展到足以使中层领导者具备复杂的职位装备的程度。本文强调了区分教师和中层领导者的两个明显区别，并提供了操作定义，详尽的描述和中层领导者特征集，以指导未来的研究和政策发展。