Attitude certainty, or the sense of conviction with which one holds one's attitude, has been the subject of considerable research attention. This article provides an overview of past, present, and future research on this topic. First, we review past work on attitude certainty, focusing on what has been learned about the antecedents and consequences of feeling certain or uncertain of one's attitude. Following this review, we examine emerging perspectives on attitude certainty. In particular, we describe recent work exploring the metacognitive appraisals that shape attitude certainty, the different meanings attitude certainty can have, and the dynamic effects of attitude certainty on attitude strength. Along the way, we also highlight important questions that have yet be answered about the certainty construct.