Lionel Shriver was born Margaret Ann Shriver on May 18, 1957 in Gastonia, North Carolina, to a deeply religious family (her father is a Presbyterian minister). At age 15, she changed her name from Margaret Ann to Lionel because she didn't like the name she had been given, and as a tomboy felt that a conventionally male name fitted her better. She was educated at Barnard College, Columbia University (BA, MFA). She has lived in Nairobi, Bangkok and Belfast, and currently lives in London.

She is married to jazz drummer Jeff Williams.

She won the 2005 Orange Prize for her eighth published novel, We Need to Talk About Kevin, a thriller and close study of maternal ambivalence, and the role it might have played in the title character's decision to murder nine people at his high school. The book created a lot of controversy, and achieved success through word of mouth.

Her journalistic experience included a spell working for The Economist. In July 2005, Shriver began writing a column for The Guardian, in which she has shared her opinions on maternal disposition within Western society, the pettiness of British government authorities, and the importance of libraries (she plans to will whatever assets remain at her death to the Belfast Library Board, out of whose libraries she checked so many books when she lived in Northern Ireland).

In 2009, she donated the short story Long Time, No See to Oxfam's 'Ox-Tales' project, four collections of UK stories written by 38 authors. Her story was published in the 'Fire' collection.

Shriver's newest book, So Much for That, was released March 2, 2010.

Shriver has offered in So Much for That a biting criticism of the US health care system, but also President Barack Obama's health care plan, and expressed this again in an interview in May 2010 while at the Sydney Writers' Festival in Australia. She has been "exasperated with the way that medical matters were run in my country" and considers that she is taking "my life in my hands. Most of all I take my bank account in my hands because if I take a wrong turn on my bike and get run over by a taxi, I could lose everything I have."