Although studies on instructional leadership are culturally and contextually specific, research in the Chinese high school settings remains scarce. This study attempts to examine the relationship between instructional leadership and the dimensions of teacher commitment with collective teacher efficacy as a mediator. Data were collected from 357 teachers in five Chinese Independent High Schools in Penang, Malaysia. Data were analyzed using partial least squares structural equation modeling method. Findings revealed that instructional leadership has a significant and direct relationship with teacher commitment to school-, students-, and teaching except the dimension of teacher commitment to profession. Collective teacher efficacy has a significant mediating effect between instructional leadership and each dimension of teacher commitment, namely commitment to school-, students-, teaching-, and profession. This study provides empirical findings for both local and international scholars to further explore the evolving dynamics between instructional leadership, collective teacher efficacy, and teacher commitment in future studies.