He is the author of a number of books and currently pursues an academic career.

Campion is a former Daily Mail astrologer, where he took over from John Naylor, the son of R. H. Naylor, the first sun sign astrologer.

His book on millenarianism, The Great Year (1994), was described by Daily Telegraph journalist Damian Thompson as "a monumental study of historical schemes".

In 1997 he founded the peer-reviewed journal Culture and Cosmos.

[7] Campion is Associate Professor in Cosmology and Culture, Director the Sophia Centre, Principal Lecturer in the Institute of Education and Humanities, and programme director of the MA programmes in Cultural Astronomy and Astrology, and Ecology and Spirituality, at the University of Wales Trinity Saint David.