A three-year project (2009-2012) in the Warwick Religions and Education Research Unit (WRERU) at the University of Warwick, funded by the ESRC/ AHRC Religion and Society Programme, explored the attitudes of 13-16-year-old pupils across the United Kingdom (England, Wales, Northern Ireland, Scotland). Despite increasing religious diversity in the UK, little was known about young people’ attitudes to religious diversity and the factors that shape such attitudes. The chapter is based on data arising from focus groups discussions with young people in British schools, drawing out how they de¿ned their (non-)religious identities and understood (non-)belief, in relation to the social contexts in which they were embedded.