Although criminal justice systems vary greatly around the world, one theme has emerged in all western jurisdictions in recent years: a rise in both the rhetoric and practice of severe punishment at a time when public opinion has played a pivotal role in sentencing policy and reforms. Despite the differences among jurisdictions, startling commonalities exist among the five countries-the U.K., USA, Canada, Australia, and New Zealand–surveyed here. Drawing on the results of representative opinion surveys and other research tools the authors map public attitudes towards crime and punishment across countries and explore the congruence between public views and actual policies. Co-authored by four distinguished sentencing policy experts, Penal Populism and Public Opinion is a clarion call for limiting the influence of penal populism and instituting more informed, research- based sentencing policies across the western world.