道德虚无主义（英语：moral nihilism或ethical nihilism），一种道德观，认为没有什幺本质上是道德或不道德的。例如，一个道德虚无主义者会说，杀人——无论出于何种原因——本身既无固有的正确性，亦无固有的错误性。道德虚无主义者认为道德来自于构建，是一套人造的复杂规则和建议。道德信奉者可能在心理，社会或经济上占据优势，但道德本身不具有绝对实在性，它甚至不具有相对实在性。

道德虚无主义既不同于道德相对主义，也不同于道德普遍主义。道德相对主义允许道德陈述，相对于文化或个人上，为真或为假，但道德虚无主义认为道德陈述在任何意义上都没有真值；道德普遍主义则认为道德陈述具有客观意义上的真假。道德虚无主义意味着道德怀疑主义（或道德怀疑论）。

This article is about the meta-ethical position. For a more general discussion of amoralism, see amorality.

Moral nihilism (also known as ethical nihilism) is the meta-ethical view that nothing is intrinsically moral or immoral. For example, a moral nihilist would say that killing someone, for whatever reason, is neither inherently right nor inherently wrong. Moral nihilists consider morality to be constructed, a complex set of rules and recommendations that may give a psychological, social, or economical advantage to its adherents, but is otherwise without universal or even relative truth in any sense.