Quality teacher–child interaction is considered one of the primary mechanisms through which educational experience fosters the development of children’s competencies. Teachers’ self-efficacy and beliefs about developmentally appropriate practices influence the quality of classroom interaction. However, the findings are mixed, and more research must be done within the preschool teacher population. The present study investigated teacher-related factors influencing teacher–child interaction quality with preschool children. Two rating scales and one observation measure were used to survey and observe 55 preschool teachers in preschool centres of Arba Minch town, Ethiopia. Statistically significant positive correlations were found between teacher factors (i.e., teacher belief, self-efficacy, teaching experience) and teacher–child interaction quality (emotional support, classroom organization, and instructional support). Teacher belief significantly predicted teachers’ emotional support and classroom organization, while teaching experience significantly predicted instructional support. The findings of this study have implications for concerned bodies striving to achieve the 2030 sustainable development goals aimed at increasing the supply of qualified teachers to ensure all girls and boys have access to quality early childhood development and care so that they are ready for primary education, especially in the least developed countries.