Using data from 3,075 teachers and 246 school leaders, this study examines the microfoundations of ambidexterity in public schools. Drawing on Coleman’s bathtub model and the concept of contextual ambidexterity, we apply multilevel structural equation modelling to show that leader trust enhances organizational ambidexterity, fully mediated by teacher commitment and individual ambidexterity. By connecting individual- and organizational-level mechanisms, the study advances public management theory and addresses a methodological gap in studies of public sector organizations. The findings offer new insights into how trust-based leadership fosters adaptive capacity in public organizations, informing leadership development and innovation strategies across the public sector.