Abstract: This paper develops a limited form of moral fictionalism: fictionalism about distinctive moral ontology, such as rights, duties, virtues, vices etc. which is not also fictionalism about who ought to do what, which outcomes are better than others, and so on. This ontological moral fictionalism has distinctive appeal, and is supported by distinctive arguments, as against rivals such as the view that we should eliminate apparent reference to distinctively moral ontology; that it can be paraphrased away; or that we should be realist or expressivist about the language of moral ontology.