Teacher-student relationships are critically important for student engagement and learning. Increasingly, children with additional behavioural, physical, communication, and learning needs are supported in the classroom by teacher aides working alongside teachers. Although the teacher aide role is often described as relational, few studies have explicitly examined the nature of the teacher aide-child relationship. This exploratory study in primary schools in Aotearoa New Zealand addresses this gap. Seven teacher aides were interviewed, and thematic analysis was used to construct common themes. The findings show that aides have time to individually know and care for each child and so develop a special relationship that is distinct from other relationships at school. In addition, the relationship is seen as essential to meet the child's needs and thus enable them to engage in their learning. The teacher aides impact positively on the child's sense of belonging, emotions, and wellbeing, which act as pathways to student engagement. Further research is needed to explore how these special and essential relationships can be optimised, and, in collaboration with teachers, improve the short- and long-term psychological, social, and educational outcomes for children.