This article defends the Harm Principle, commonly attributed to John Stuart Mill, against recent criticism. Some philosophers think that this principle should be rejected, because of severe difficulties with finding an account of harm to plug into it. I examine the criticism and find it unforceful. Finally, I identify a faulty assumption behind this type of criticism, namely that the Harm Principle is plausible only if there is a full-blown, and problem-free, account of harm, which proponents of the principle can (...) refer to. (shrink)