Observers have expressed concerns that democratic politics is growing more personalistic. The absence of cross-national time-series data capturing personalism in democracies, however, has made it difficult to assess the validity of these observations. This study fills that gap. It covers a time-varying index of personalism in the world’s democracies from 1991 to 2020. The index combines original data measuring indicators of personalism with existing data sources. We find that observers’ intuitions are correct: Levels of personalism have increased in democracies in recent years. Importantly, we show that greater personalism is associated with a variety of negative outcomes, such as higher levels of populism, a higher probability of democratic erosion, and greater political polarization. In addition, we explore the potential causes of the personalist wave and find evidence that new technologies and digital tools are facilitating it. Our new index of personalism enables researchers to better explore these and other relationships. Given that a key signal of impending personalization is the leader’s creation of their own political party, we encourage observers to take note of the election of such leaders as a red flag for democracy.