Few topics in public opinion research have attracted as much attention in recent years as partisan polarization in the American mass public. Yet, there has been considerably less investigation into whether peopleperceive the electorate to be polarized and the patterns of these perceptions. Building on work in social psychology, we argue that Americans perceive more polarization with respect to policy issues than actually exists, a phenomenon known as false polarization. Data from a nationally representative probability sample and a novel estimation strategy to make inferences about false polarization show that people significantly misperceive the public to be more divided along partisan lines than it is in reality. Also, people’s misperceptions of opposing partisans are larger than those about their own party. We discuss the implications of these empirical patterns for American electoral politics.