Few studies have undertaken rigorous comparative analyses of levels of ethnic residential segregation across two or more countries. Using data for the latest available censuses (2000–2001) and a bespoke methodology for such comparative work, this article analyzes levels of segregation across the urban systems of five major immigrant-receiving, English-speaking countries: Australia, Canada, New Zealand, the United Kingdom, and the United States of America. After describing the levels of segregation in each, the article tests a model based on generic factors that should influence segregation levels in all five countries and then evaluates—for the urban population as a whole, for the “charter group” in each society, and for various ethnic minority groups—whether there are also significant country-specific variations in segregation levels. The findings show common factors influencing segregation levels in all five countries: notably the size of the group being considered as a percentage of the urban total, but also urban size and urban ethnic diversity, plus country-specific variations that cannot be attributed to these generic factors. In general there is less segregation in Australia and New Zealand than in the other three countries.