Using exceptionally detailed administrative data on all 412,000 students attending university in the United Kingdom in 2014–2015 combined with spatial census data from 2011, we explore for the first time how the ethnic composition of where students grow up is linked to where they attend university. We calculate a “diversity score” for every U.K. university, which is then compared with the ethnic diversity of the surrounding area, allowing us to explore the institutional geography of ethnicity in U.K. universities. These scores provide the basis for a multilevel analysis of factors influencing whether students move towards more or less ethnically diverse universities than where they have grown up. White students are more likely than their ethnic‐minority peers to move towards a university that is more diverse than their home neighbourhood. We thus explore how students' mobility decisions for university are influenced by the uneven geography of race in U.K. cities and universities.