This paper argues for an account of insincerity in speech according to which an utterance is insincere if and only if it communicates something that does not correspond to the speaker's conscious attitudes. Two main topics are addressed: the relation between insincerity and the saying-meaning distinction, and the mental attitude underlying insincere speech. The account is applied to both assertoric and non-assertoric utterances of declarative sentences, and to utterances of non-declarative sentences. It is shown how the account gives the right results for a range of cases.