Constructivism in ethics is the view that insofar as there are normative truths, for example, truths about what we ought to do, they are in some sense determined by an idealized process of rational deliberation, choice, or agreement. As a “first-order moral account”--an account of which moral principles are correct-- constructivism is the view that the moral principles we ought to accept or follow are the ones that agents would agree to or endorse were they to engage in a hypothetical (...) or idealized process of rational deliberation. As a “metaethical account” – an account of whether there are any normative truths and, if so, what they are like – constructivism holds that there are normative truths. These truths are not fixed by facts that are independent of the practical standpoint, however characterized; rather, they are constituted by what agents would agree to under some specified conditions of choice. In working to provide a more precise definition of constructivism in metaethics, the focus of this entry, one faces two main difficulties. The first difficulty is that constructivism comes in several varieties, each of which claims a different niche within metaethics, and some claim no space at all. The second difficulty concerns where to place constructivism on the metaethical map in relation to realism and anti-realism. These are terms of art, and it is highly contested which views count as realist and which as antirealist. These two difficulties will be addressed in what follows by focusing on the distinctive questions that constructivist theories are designed to answer. Section §1 defines the scope of constructivism in ethics, in contrast to constructivism in political theory. Sections §§2-5 illustrate the main varieties of metaethical constructivism, which are designed to account for the nature of normative truths and practical reasons. Section §6 presents the main varieties of constructivist accounts of the justification of moral judgments of right and wrong. Section §7 discusses the metaethical status of constructivism, and its distinctive import. (shrink)