Alison Joseph was born and brought up in London. She studied French and Philosophy at Leeds University, and then worked in local radio in Leeds as a producer and presenter. She moved back to London in 1983 and worked for a Channel 4 production company, making short documentaries. In 1985 she set up her own company, Works on Screen. Productions included Through the Devil's Gateway, a series about women and religion presented by Helen Mirren, which was broadcast by Channel 4 in 1989. A book of the series was published by SPCK. Sister Agnes became a reality with the publication of Sacred Hearts in 1994. This was followed by The Hour of Our Death (1995), The Quick and the Dead (1996), A Dark and Sinful Death (1997), The Dying Light (1999) and The Night Watch (2000). All the Sister Agnes books are published by Headline in the UK, and the first two are published in the US by St. Martin's Press.

Alison has also written short stories for Radio 4, for YOU magazine, for Critical Quarterly and for various women's magazines, as well as abridging novels for Radio 4's Book at Bedtime and The Late Book, including the award-winning production of Captain Corelli's Mandolin. She is the author of two radio plays, both broadcast on Radio 4, Go For The Grail (1995) and Baby on Board (1996).

Alison lives in London with her husband and three children.