Prejudice and discrimination toward immigrants, and the consequences of these negative attitudes and behavior, are key determinants of the economic, sociocultural, and civic-political future of receiving societies and of the individuals who seek to make these societies their new home. In this article I review and organize the existing literature on the determinants and nature of prejudice and discrimination toward immigrants, summarizing what we know to date and the challenges in attributing effects to immigrant status per se. I also discuss the consequences of discrimination against immigrants for immigrants themselves, their families, and the societies in which they settle. I conclude by presenting key research questions and topics in this domain that should be at the top of the research agenda for those interested in intergroup relations in this age of mass migration. Expected final online publication date for the Annual Review of Psychology, Volume 72 is January 4, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.