More than 26,000 Muslim pupils are enrolled in Catholic schools in England and Wales. For the first time an annual census of Catholic schools has collected information on the number of pupils from other religions.
The biggest group of non-Catholic pupils are from other Christian denominations - but almost a tenth are from Muslim families.
The government has plans to encourage more Catholic free schools to open. This analysis shows that, overall, nearly a third of the more than 850,000 pupils within the Catholic school system are not Catholic - a total of almost 290,000. This can reflect local demographic changes and migration - with Catholic schools serving areas with a declining number of Catholic families.
The Muslim pupils are the biggest non-Christian group, apart from the 63,000 who are from non-religious families.
Finnuala Nelis, head of St Patrick's Catholic Voluntary Academy in Sheffield, is in charge of a school where about half the pupils are not Catholics. She says there have been changes in the local population - and that the school is now popular with parents who choose a Catholic school, even though they are not Catholics.
This includes Christians from a number of African churches and also Muslim pupils. She says there are Muslim pupils who regularly attend their local mosques, but who will go to Catholic religious services at school.
