Kathleen Mary Louise "Kate" O'Brien was born in Limerick City in 1897. Following the death of her mother when she was five, she became a boarder at Laurel Hill Convent. She graduated in English and French from the newly established University College, Dublin, and she then moved to London, where she worked as a teacher for a year.[1]

In 1922–23, she worked as a governess in the Basque Country, in the north of Spain, where she began to write fiction.[2] Upon her return to England, Kate O'Brien worked at the Manchester Guardian.[3] After the success of her play Distinguished Villa in 1926, she took to full-time writing and was awarded the 1931 James Tait Black Prize for her debut novel Without My Cloak. Kate O'Brien is best known for her 1934 novel The Ante-Room, her 1941 novel The Land of Spices, and the 1946 novel That Lady.[4]

Many of her books deal with issues of female agency and sexuality in ways that were new and radical at the time. Her 1936 novel, Mary Lavelle, was banned in Ireland and Spain, while The Land of Spices was banned in Ireland upon publication.[5] In addition to novels, she wrote plays, film scripts, short stories, essays, copious journalism, two biographical studies, and two very personal travelogues. Throughout her life, O'Brien felt a particular affinity with Spain—while her experiences in the Basque Country inspired Mary Lavelle, she also wrote a life of the Spanish mystic Teresa of Avila, and she used the relationship between the Spanish king Philip II and Maria de Mendoza to write the anti-fascist novel That Lady.

O'Brien wrote a political travelogue, Farewell Spain, to gather support for the leftist cause in the Spanish Civil War, and it has been argued that she was close to anarchism in the 1930s.[2] A feminist, her novels promoted gender equality and were mostly protagonised by young women yearning for independence. Kate O'Brien's determination to encourage a greater understanding of sexual diversity — several of her books include positive gay/lesbiancharacters —, make her a pioneer in queer literary representation.[6] She was very critical of conservatism in Ireland, and by spearheading a challenge to the Irish Censorship Act, she helped bring to an end the cultural restrictions of the 1930s and 40s in the country.[7] Like many other Irish writers and artists, she lived much of her life in England. She died in Faversham, near Canterbury, in 1974.[4]

The Glucksman Library at the University of Limerick holds an important collection of O'Brien's writings.[4] In August 2005, Penguin reissued her final novel, As Music and Splendour (1958), which had been out of print for decades. The Kate O'Brien Weekend, named in her honour, takes place in Limerick every year, attracting academic and non-academic audiences (the event includes one or two lectures on O'Brien).

In the classic film Brief Encounter (1945), the co-protagonist Celia Johnson says she has reserved "the latest Kate O'Brien" at her local library, which prepares the audience for the moral dilemmas that the character is about to face. This offers a good example of how popular Kate O'Brien was in the 1940s, before falling into obscurity for decades, only to be 'rediscovered' as a key writer in the 1980s.

In the 1930s one of the notorious members of Ferguson's Gang adopted the pseudonym 'Kate O'Brien the Nark' in tribute to Kate.[8]∼Irish novelist and playwright. O'Brien was the author of "That Lady" (1955) and "Talk of Angels" which was released in 1998, 24 years after her death.