What is the relation between norms (in the sense of 'socially accepted rules') and conventions? A number of philosophers have suggested that there is some kind of conceptual or constitutive relation between them. Some hold that conventions are or entail special kinds of norms (the 'conventions-as-norms thesis'). Others hold that at least some norms are or entail special kinds of conventions (the 'norms-as-conventions thesis'). We argue that both theses are false. Norms and conventions are crucially different conceptually and functionally in ways that make it the case that it is a serious mistake to try to assimilate them. They are crucially different conceptually in that whereas conventions are not normative and are behaviour dependent and desire dependent, norms are normative, behaviour independent, and desire independent. They are crucially different functionally in that whereas conventions principally serve the function of facilitating coordination, norms principally serve the function of making us accountable to one another.