The term "common good" names the end (or final cause) of political and social life in the tradition of moral thought that owes its main substance to Aristotle and St. Thomas Aquinas. It names a genuine good ("bonum honestum") and not merely an instrumental or secondary good defeasible in the face of particular goods. However, at the same time, it does not override or subsume such goods. The good of individual persons and other groups is in an important way constitutive of the common good in this classical conception. To see this we need first to consider the way the classical view understands the good of individual persons and then turn back to the common good. After discussing several important aspects of the political common good I will then consider a common objection to the notion of the common good and suggest some unresolved problems.