What are the ideological sources of free trade attitudes? Free trade plays a crucial role in classical liberal theory as a way of increasing the prospects of peace between states. Are liberal individuals more supportive of free trade? The literature on foreign policy beliefs largely neglects the question of trade, and those exceptions that find support for the liberal hypothesis generally rely on faulty conceptualization. Using surveys of the American mass public and American elites, this article finds that the combination of views that marks classical liberalism does not in fact predict support for free trade at either the mass or the elite level. Support for free trade at the mass level has libertarian, not liberal, foundations, predicted by a combination of social and economic libertarianism. At the mass level, the combination of cosmopolitanism and dovishness that constitutes foreign policy liberalism has no effect on trade attitudes. At the elite level, cosmopolitanism is actually generally negatively associated with support for free trade. Free trade is a wedge issue that creates strange alliances at the elite level between cosmopolitans and isolationists generally hostile to one another on foreign policy and at the mass level between social and economic libertarians typically antagonistic to each other's domestic agenda.