In this chapter, the rise, peak, and transformation of the Australian steel industry, particularly its dominance during the mid-twentieth century under BHP’s vertically integrated structure, is examined. Strategic plant locations, especially Newcastle and Port Kembla, supported strong growth through the 1960s, when steel intensity in the economy was at its highest. Although demand for steel later declined with the shift towards mineral exports and reduced manufacturing, the industry remains vital to infrastructure, trade, and national security.