Research Findings: This study aims to extend our knowledge regarding contributions of educator--child interactions to child language outcomes by examining the extent to which specific dimensions of the CLASS observational tool of educator-child interactions are associated with child language abilities, utilizing data from an Australian longitudinal study of over 2,000 children attending formal Early Childhood Education and Care (ECEC). The analysis included a novel measurement model fitted to the data to allow each CLASS dimension to be modeled separately. Results showed that each CLASS dimension was associated with initial average language abilities. Small, negative effects of Emotional Support dimensions on growth of children's average Understanding Directions score were found, but there were no associations between any of the dimensions and average growth in Verbal Ability. None of the Instructional Support dimensions (which are language focused) predicted growth in language abilities. These null findings are addressed in the discussion. Practice or Policy: Findings from this study illustrate that, typically, ECEC programs rate low on dimensions of quality developed to capture language-promoting educator-child interactions. Findings also suggest a selection effect related to equity of access to classroom quality with children with the highest initial language abilities in the highest quality classrooms.