--- - |2 Abstract Childhood disability has been largely overlooked in social stratification and life course research. As a result, we know remarkably little about mechanisms behind well‐documented disability differentials in educational outcomes. This study investigates educational transitions of disabled youth using data from the Longitudinal Study of Young People in England. We draw on social stratification literature on primary and secondary effects as well as that on stigma and labelling in order to explain disabled young people's educational outcomes. We find that disability differentials in transition rates to full‐time academic upper secondary education and to university are largely the result of primary effects, reflected in differences in school performance between disabled and non‐disabled young people. However, we also find evidence for secondary effects, with similarly achieving disabled young people less likely to pursue full‐time academic upper secondary education compared to their non‐disabled peers. We examine the extent to which these effects can be explained by disabled youth's suppressed educational expectations as well as their experiences of being bullied at school, which we link to the stigma experienced by disabled young people and their families. We find that educational expectations play an important role at crucial transitions in the English school system, while the effect of bullying is considerably smaller. By drawing attention to different social processes contributing to disability differentials in attainment, our study moves beyond medical models that implicitly assume a naturalized association of disability with poor educational outcomes, and demonstrates the parallels of disability with other ascriptive inequalities. - 'The British Journal of Sociology, EarlyView. '