I argue that although Paul Grice’s picture of conversational maxims and conversational implicature is an immensely useful theoretical tool, his view about the nature of the maxims is misguided. Grice portrays conversational maxims as tenets of rationality, but I will contend that they are best seen as social norms. I develop this proposal in connection to Philip Pettit’s account of social norms, with the result that conversational maxims are seen as grounded in practices of social approval and disapproval within a given group. This shift to seeing conversational maxims as social norms has several advantages. First, it allows us to neatly accommodate possible variation with respect to the maxims across well-functioning linguistic groups. Second, it facilitates a more psychologically plausible account of flouting. And third, it generates insights about the nature of social norms themselves.