In 2014 the British government called on schools to actively promote fundamental British values (FBVs), seeing this as an effective way to prevent the radicalisation of young people. The government considers these values to include democracy, individual liberty, the rule of law and respect for people of different backgrounds and religions. Rather than criticising this policy on theoretical or ideological grounds, as many studies have done, the current article aims to ascertain support for the values labelled as fundamentally British among 23 year olds in England and to assess whether levels of support are associated with educational attainment and distinct educational practices experienced earlier in life. Data from the Citizenship Education Longitudinal Study (CELS) are analysed for these purposes. A multidimensional measure of FBVs is constructed based on policy understandings of the term rather than statistical considerations. The article finds that levels of support for FBVs among 23 year olds are already very high and do not differ between the White British majority and various minority ethnic groups, although the small sample sizes of the latter do not allow for strong conclusions about these differences. Among the educational conditions, educational attainment and particularly track attended appears to be the only influential condition, with those obtaining academic qualifications showing significantly higher support for FBVs than those achieving vocational ones. Adding this variable to the model neutralises the effects of specific programmes or pedagogies experienced during lower secondary, such as citizenship education, an open climate of classroom discussion or school‐based political activities.