The 16.9 per cent increase in entries in 2005 is almost twice that of the next fastest-growing subject, political studies.
Dr Ellie Johnson Searle, director of the Joint Council for Qualifications, said: "The rise in entries for religious and political studies is significant at a time when Britain increasingly needs young people to understand the complexities of our faith communities and participation in our democratic society."
The growth in the subject reflects increased interest in religion among young people despite claims that society is becoming ever more secular.
Last year there was also a 6.6 per cent rise in the number of pupils taking GCSE religious education, from 132,304 in 2003 to 141,037 in 2004, in part because of the introduction of a new short course in the subject.
Applications to teach RE are also on the rise, says the Teacher Training Agency, amid a chronic shortage of REteachers.