When may someone complain, morally? And what, if any, is the relationship between legitimate moral complaint and one's own behaviour? I point out a perplexity about a certain class of moral complaints. Two very different conceptions of moral complaint seem to be operating, and they often have contrary implications. Moreover, both seem intuitively compelling. This is theoretically and practically troubling, but has not been sufficiently noticed. The Paradox of Moral Complaint seems to point to an inherent difficulty in our reflective moral intuitions. Given the legislative nature of moral agency, the plausible limitations upon reasonable moral complaint seem to contradict the inviolability of central moral constraints and the complaints they allow. In the sort of cases under discussion, morality seems at once both to insist upon the possibility of moral complaint, and to deny it.