This chapter examines how the ‘Indo–Pacific’ concept became entrenched as the primary frame of reference for Australian regional security between 2016 and 2020. It first briefly reviews the process by which the ‘Asia–Pacific’ descriptor was jettisoned in favour of the ‘Indo–Pacific’ to capture Australia’s conception of its region and its place therein, and how this affected related policies. The chapter next examines Australia’s efforts to engage the region’s major powers, as well as the sub-regions of Southeast Asia and the South Pacific, to illustrate how the Indo–Pacific framework governed Australia’s approach to regional security. Australia’s enunciation of the Indo–Pacific concept, the chapter shows, facilitated closer relations with the US, Japan and India, but it created frictions with China and gained only limited acceptance in Southeast Asia and the South Pacific.