High-quality early childhood education is critical to young children’s development. Children participate in diverse classroom activities, and examining how their time is allocated can provide important insights into the quality of early childhood education (ECE). This study analyzed classroom activity time allocation in early childhood education across U.S. center-based and home-based childcare settings using data from the 2019 National Survey of Early Care and Education. Five activities were examined: whole-group, small-group, one-on-one instruction, child-directed activities, and screen time. The survey sample included 6,333 teachers, primarily female, with diverse racial/ethnic backgrounds. Results revealed that whole-group instruction remains common, high-quality practices match whole-group time, and screen time is higher in home-based settings. Factors including teacher education, professional development, child-centered beliefs, and class size are significantly related to time allocation. Policy and practical implications are discussed.