Recent studies report high levels of physical inactivity among most of the global population, including young children. As young children spend a large fraction of their time in school, early childhood teachers have important roles in promoting adequate physical activity (PA) among children. This scoping review aims to synthesise existing evidence on early childhood teachers' understanding of PA in early childhood education and care (ECEC) settings based on research in the past decade. Following the framework proposed by the Joanna Briggs Institute, we searched databases including PubMed, PsycINFO, SportDiscus, ERIC, Web of Science, Scopus, and Education Research Complete. A total of 13 articles were deemed eligible for review. The results reveal early childhood teachers' positive and negative views towards PA in ECEC settings, as well as what they consider facilitators and barriers to PA. Most of the studies call for further professional development of early childhood teachers specific to PA. Future research is also recommended to fill gaps and examine how early childhood teachers' understanding aligns with their local policies and curricula.