Boylan is born in Dublin on April 21, 1948, the youngest of three daughters of Patrick Boylan, a clerk, and his wife Evelyn (née Selby). Her mother feels trapped by the limitations that domesticity imposes on women in 1950s Ireland, and had wanted to have a writing career. She encourages her daughter to send off stories and poems to newspapers. The first piece is published when she is 14, and she wins a prize in the national Texaco Children’s Art Competition when she is about 10 years old.
After leaving St. Louis convent, Boylan takes a job as a sales assistant in a bookshop before beginning her career as a journalist at The Irish Press, now defunct. She marries Alan Wilkes, a journalist who is a colleague at The Irish Press, in St. Patrick’s Church in Straffan, County Kildare, on September 18, 1970. In 1974 she wins the Journalist of the Year award when working in the city for the Evening Press. Later in her career she edits the glossy magazine Image, before largely giving up journalism to focus on a career as an author.
Boylan’s novels are Holy Pictures (1983), Last Resorts (1984), Black Baby (1988), Home Rule (1992), Beloved Stranger (1999), Room for a Single Lady (1997), which wins the Spirit of Light Award and is optioned for a film, and Emma Brown (2003). The latter work is a continuation of a 20-page fragment written by Charlotte Brontë before her death.
Boylan’s short stories are collected in A Nail on the Head (1983), Concerning Virgins (1990) and That Bad Woman (1995). The film Making Waves, based on her short story “Some Ladies on a Tour”, is nominated for an Oscar in 1988.
Boylan’s non-fiction includes The Agony and the Ego (1994) and The Literary Companion to Cats (1994). She writes introductions to the novels of Kate O’Brien and Molly Keane and adapts Keane’s novel Good Behaviour as the classic serial for BBC Radio 4 (2004). Her work has been translated as far afield as Russia and Hong Kong.
In later life, Boylan lives in County Wicklow with her husband. When she is diagnosed with ovarian cancer, she faces her illness with characteristic strength. She takes up kickboxing and spends time in France, shopping, cooking and entertaining friends. She succumbs to cancer at the age of 58 on May 16, 2006.