We characterize rates of intergenerational income mobility at each college in the United States using administrative data for over 30 million college students from 1999-2013. We document four results. First, access to colleges varies greatly by parent income. For example, children whose parents are in the top 1% of the income distribution are 77 times more likely to attend an Ivy League college than those whose parents are in the bottom income quintile. Second, children from low and high-income families have very similar earnings outcomes conditional on the college they attend, indicating that there is little mismatch of low socioeconomic status students to selective colleges. Third, upward mobility rates – measured, for instance, by the fraction of students who come from families in the bottom income quintile and reach the top quintile – vary substantially across colleges. Much of this variation is driven by di↵erences in the fraction of students from low-income families across colleges whose students have similar earnings outcomes. Mid-tier public universities such as the City University of New York and California State colleges tend to have the highest rates of bottom-to-top quintile mobility.