Arthur Calwell was the major architect of Australia's successful post-war migration program that laid the demographic, economic and cultural foundations of contemporary society. In public memory, however, Calwell is now mostly associated with the White Australia policy, which aimed to preserve Australia as a white, British-Australian society by severely restricting Asian immigration. This article assesses Calwell's leadership of the immigration program, his impact and his legacy. It identifies three distinct, often irreconcilable leadership characteristics, defined in terms of him as “innovative policy-maker’, “political broker” and “agitator”. This focus on leadership challenges the one-dimensional view of Calwell that exists in Australian political historiography. It is also intended to extend our engagement with leadership studies and illuminate the role leadership plays in political decision-making, especially sensitive portfolios like immigration.