[3] Her memoir I Am, I Am, I Am: Seventeen Brushes with Death reached the top of the Sunday Times bestseller list.

[9] O'Farrell worked as a journalist, both in Hong Kong and as deputy literary editor of The Independent on Sunday in London.

O'Farrell's numerous successful novels, including the Costa Award-winning The Hand that First Held Mine, have received widespread critical acclaim.

[11] From 2020 to 2022, O'Farrell published two pictures books for children, Where Snow Angels Go and The Boy Who Lost His Spark, both illustrated by Daniela Jaglenka Terrazzini.

[12][13] O'Farrell was the invited castaway on the BBC Radio 4 programme Desert Island Discs in March 2021.

[14] In 2022, she published The Marriage Portrait, a novel based on the short life of Lucrezia de' Medici, who may or may not have been poisoned by her husband, Alfonso II, Duke of Ferrara.

[16] In April 2023, the Royal Shakespeare Company's stage adaptation of Hamnet previewed at the newly opened Swan Theatre in Stratford-upon-Avon.

[17] In January 2024, it was reported that Chloé Zhao was planning to adapt Hamnet for the screen alongside O'Farrell.

[19] O'Farrell is married to a fellow writer, William Sutcliffe, whom she met while they were students at Cambridge; they didn't become a couple, however, until ten years or so after they graduated.