This study investigates the influence of principal instructional leadership on teachers' effort to employ instructional strategies for nurturing student autonomy in learning. Nationally representative multi-level data for 7,879 teachers in 479 middle schools in Australia, Malaysia, and South Korea were analyzed in this study. In all three countries analyzed, principal instructional leadership was significantly positively associated with teachers' use of autonomy-supportive instruction. This significant association persisted even when a range of other variables was simultaneously taken into account. This result gives credence to the hypothesis that teachers, who work in a school where the principal effectively demonstrates greater instructional leadership, tend more likely to actively integrate elements of teaching for learner autonomy into their instructional practice.