In the past two decades, the development of education for persons with special educational needs in Ireland has reflected the international trend to develop more inclusive educational policies and has led to significant growth in the number of pupils with SEN attending mainstream primary schools. This research considers approaches to leadership and management in inclusive and special education in eight mainstream primary schools. It adds to existing literature by exploring the role of the Special Educational Teacher (SET) with responsibility for the day-to-day provision of special education from the perspectives of the eight SETs and their principals. The study identified the responsibilities, tasks, and duties of those coordinating SEN provision, both formally as part of the in-school management (ISM) team and informally as part of the SEN structure, and the factors that help them fulfil those responsibilities. The extent to which these teachers initiate change and innovation in their schools was also examined. The research comprised a case study approach, with data generated through qualitative research involving focus group interviews, followed by one-to-one semi-structured interviews with SETs and their principals. Reflective diaries were also maintained by the SETs. Findings indicate that school context is fundamental to the SETs’ capacity to lead and influence SEN provision. Shared leadership is evident, with collaborative professionalism and collective initiative existing in all schools, particularly in the implementation of coteaching approaches. Both formal and informal planning structures are evident, facilitating school-based collaboration and dialogue, principally led by the SET. There is a lack of opportunities to acquire formal qualifications in SEN in the region where the study took place. However, a proposal is provided for the development of in-school communities of practice which could create a sustainable model of professional learning. Increased individual and collective teacher autonomy in SEN provision has recently proved challenging for schools. The findings indicate a lack of confidence in relation to the additional responsibility of SEN resource allocation. A proposal to establish school-toschool networks focussed on SEN matters is offered which may alleviate teacher concerns and provide support and opportunities for mutual dialogue and collective initiatives.