Australia is among the most prominent advocates of the Indo-Pacific concept that increasingly serves as a new point of convergence between the United States and its Asian allies and partners. In contrast to this upgraded Indo-Pacific orientation, however, a vigorous debate is playing out in Australia regarding the merits of this concept and its supporting pillars, such as the idea of a rules-based international order and the resuscitated Quadrilateral Security Dialogue (or Quad). This article traces the competing perspectives in that debate. While not anticipating any imminent shift in Canberra's official support for the Indo-Pacific concept, the argument is advanced here that Australia's Indo-Pacific debate requires careful monitoring. Precisely because Canberra's Indo-Pacific advocacy has been so prominent, any deviation from this posture could have negative ramifications for the Indo-Pacific concept's broader pervasiveness and sustainability, particularly among America's Southeast Asian allies and partners who are now only beginning to embrace it.