Value-pluralism is the idea that two or more moral values may be equally ultimate (true), yet in conflict. In addition, value-pluralism postulates that in many cases, such incompatible values, may be rationally incommensurable. As such, value-pluralism is a theory in metaethics, rather than an ethical theory or a set of values in itself. The Oxford historian of ideas, Isaiah Berlin, is accredited with having done the first substantial work on value-pluralism, bringing it to the attention of general academia. Joseph Raz has attempted to further clarify value-pluralism.

Value-pluralism is an alternative to value-relativism (or 'moral relativism'), and also, to value-universalism (or 'moral absolutism'). An example of value-pluralism is where the moral life of a nun is incompatible with that of a mother (e.g. celibacy in the case of the former precludes motherhood). Yet, there is no purely rational measure which says that either is preferable to the other. Hence, moral choices are often radical preferences with no rational calculus to judge which choices are to be made.

Value-pluralism differs from value-relativism because it accepts limits to differences, such as when vital human needs are violated. It differs from value-universalism because it rejects the notion that there is any one universally valid moral system.