Poor quality early childhood education and care (ECEC) can be detrimental to the development of children as it could lead to poor social, emotional, educational, health, economic, and behavioural outcomes. The lack of consensus as to the strength of the relationship between teacher qualification and the quality of the early childhood learning environment has made it difficult for policymakers and educational practitioners alike to settle on strategies that would enhance the learning outcomes for children in their early stages of education. This Campbell systematic review examines the current empirical evidence on the correlation between teacher qualifications and the quality of the early childhood learning environments. The review summarises findings from 48 studies with 82 independent samples. Studies included children from pre-kindergarten and kindergarteners prior to elementary/primary school and centre-based providers. Included studies must have examined the relationship between teacher qualification and quality of the ECEC environment from 1980 to 2014, as well as permit the identification of the education program received by the lead teacher and provide a comparison between two or more groups of teachers with different educational qualifications. The studies had to have comparative designs and report either an overall quality scale or an environment rating scale. Overall, the results show that higher teacher qualifications are significantly correlated with higher quality early childhood education and care. The education level of the teachers or caregivers is positively correlated to overall ECEC qualities measured by the environment rating scale. There is also a positive correlation between teacher qualification and subscale ratings including program structure, language, and reasoning. The results are important for governments and stakeholders wanting to improve early childhood services to enhance children and family outcomes. Mandating qualified teachers, i.e. with tertiary education, may lead to significant improvement for both process and structural quality within centre-based and home-based ECEC settings. A coding sheet is appended.