Born in Limerick and raised in Monkstown, Keyes earned a law degree from Dublin University, but immediately disregarded it, left Ireland and became a waitress in London, feeling as though she did not deserve a well-paid career. Keyes began composing short stories after she found work in an accounts office, but initially had no intention of completing a novel, arguing that it would take too long.

In this period of her life, she underwent a severe struggle with alcoholism, but overcame this in 1995 at a rehabilitation center in Dublin, Ireland.

However, following a letter back from the publisher whom she'd sent her manuscripts to, she began work on a book, and thus her first feature-length story, Watermelon, was born. Known for her self-deprecation, Keyes often says that she "became a writer by accident".

Although many of her novels are known as comedies, they are often filled with dark themes including domestic violence, drug abuse, mental illness, divorce and alcoholism, most of which are loosely based on her own life experiences.

She is regarded by her fans as a pioneer of the so-called 'chick-lit' genre; her stories usually revolve around a strong female character who overcomes numerous obstacles to achieve lasting happiness.

Keyes currently lives in Dun Laoghaire with her husband Tony, after moving back from London in 1997. She suffers from severe clinical depression, and attempted suicide in 1994; she has since talked frankly about her battle with the disease.

Fiction

• Watermelon (1995)
• Lucy Sullivan is Getting Married (1996)
• Rachel's Holiday (1998)
• Last Chance Saloon (1999)
• Sushi for Beginners (2000)
• No Dress Rehearsal (2000)
• Angels (2002)
• The Other Side of the Story (2004)
• Nothing Bad ever Happens in Tiffany's (2005)
• Anybody Out There? (2006)
• This Charming Man (2008)
• The Brightest Star in the Sky (2009)

Non-fiction

• Under the Duvet (2001)
• Further under the Duvet (2005)
• Cracks In My Foundation in Damage Control - Women on the Therapists, Beauticians, and Trainers Who Navigate Their Bodies edited by Emma Forrest {2007)