Objectives Research on the immigration-crime link has grown substantially yet researchers have not sufficiently considered immigrant heterogeneity, which reflects both the number of immigrant groups in a community and their relative sizes or representation, even as theory has a lot to say regarding the possible impact of such heterogeneity. With few exceptions, scholars have yet to consider how immigrant diversity, including by race/ethnicity, country of origin, or language use, may matter for the immigration-crime association. This is the focus of the current study. Methods Building on a handful of studies, we examine the association between measures of immigrant heterogeneity based on different social dimensions and crime rates across 15,000 neighborhoods in roughly 350 U.S. cities, reflecting a wide range of immigrant community contexts. Results We find that immigrant diversity matters greatly for neighborhood crime rates, although in unique ways. Conclusions We discuss the implications of our findings for theories that emphasize the consequences of heterogeneity specifically, and for the immigration-crime relationship more generally.