 That the object of moral concern in public health is the public rather than individuals (Rose 1985; Rose et al. 2008; Coggon 2012) raises a conceptual question: what or who is the public? While interesting in its own right, this question is also important because it informs justificatory challenges that public health ethics has to address: who is public health good for? Whose health are we concerned with, and what sacrifices is it acceptable to ask of individuals in order to achieve it? And why is public health a good worth promoting?