Her father taught Greek and Latin at St. Paul’s School. She was baptized a protestant but was converted to Catholicism at the age of 7 when her father converted. She struggled with religion and did not feel that she fitted in with the other girls at her school, many of whom were from upper-class Catholic families. Although she was educated at a convent school, The Convent of the Sacred Heart, Roehampton (later Woldingham School, Surrey), she did not find faith in the Church at that time.

Although she is remembered as a modernist writer, she developed a terrible fear of writing after a misunderstanding when she was 15. She had been working on what was going to her first novel, which was to be a present for her father. She wanted to surprise him with a book about wicked people whose lives are changed as they discover religion. She attempted to give a detailed description of the evil characters, but, because of her lack of experience, she was unable to describe their wickedness except to say that they “Indulged in nameless vices”. This dark story was found unfinished by officials at her Catholic school and she was then expelled from the school without being given the opportunity to explain her book. She describes this incident as being her most vivid and tragic memory. “My superb gift to my father was absolutely my undoing” she remarked in an interview. She did not begin writing novels again until 20 years later, when her father died.

After she was expelled from the convent at Roehampton, she attended her father’s school, St. Paul’s, but did not fit in there either. When she left school she attempted to become an actress, but was unsuccessful. She then wrote for magazines and worked in advertising, where she earned £250 a year promoting Mercolized wax. She spent nine years working as a copywriter in London and she also worked for the BBC as a translator.Antonia White's translations of Colette's 'Claudine' novels were recognised for their elegance and erudition and remain the standard texts today.

In 1921 she was married to the first of her three husbands. The marriage was annulled only 2 years later, and reportedly was never consummated. She immediately fell in love again with a man named Robert, who was an officer in the Scots Guards. They never married, and their relationship was brief but intense, which led to her experiencing a severe mental breakdown. She was committed to Bethlem, a public asylum, where she spent the next year of her life.

She had described her breakdown as a period of “mania”. After she left the hospital, she spent four years participating in Freudian studies. She struggled the rest of her life with mental illness which she referred to as “The Beast”.

Her second marriage was to a man named Eric Earnshaw Smith, but this marriage ended in divorce. By the age of 30, she had been married 3 times. During her second marriage, she had fallen in love with two men. One was an unknown and one that she kept to herself, speaking of only fleetingly. The other was a man named Tom Hopkinson, a copywriter and S.G. who is described as “a tall handsome young man with a slightly melancholy charm”. She had trouble deciding whom she should marry following her divorce, and she married Hopkinson in 1930. She had two daughters, Lyndall Hopkinson and Susan Chitty, who have both written autobiographical books about their hard and difficult relationship with their mother.

By 1931, she was married to Tom Hopkinson and was friends with novelist Djuna Barnes, and she was with Barnes when the latter wrote her now famous novel depicting a lesbian affair gone bad, Nightwood. This novel was based on Barnes's relationship with Thelma Wood. In 1933, White completed her first novel, Frost in May, which fictionalized her experiences at Catholic boarding school and her expulsion. She also began writing a second novel, but a failed marriage and mental illness hindered its completion.

Fifteen years later, she completed her second novel The Lost Traveller, which was published in 1950. In the subsequent five years, after undergoing treatment for mental illness and reconverting to Catholicism, she completed the Clara Batchelor trilogy, which includes The Lost Traveller, about her relationship with her mother and father, The Sugar House, about her first unconsummated marriage, and Beyond the Glass, about an intense love-affair followed by a breakdown which is vividly described. As with her previous work, the trilogy was fictional, but mainly autobiographical.

The four novels together narrate her life from age nine to age twenty-three. In 1966, she published a collection of letters entitled The Hound and the Falcon: The Story of a Reconversion to the Catholic Faith. She also wrote Three in a Room, a three-act comedy, as well as many short stories, poems and juvenile fiction.

Her career as a writer seems to have been driven by the desire to cope with a sense of failure, resulting initially from her first attempt at writing, and with mental illness. She was quoted as saying, “The old terrors always return and often, with them, a feeling of such paralyzing lack of self-confidence that I have to take earlier books of mine off their shelf just to prove to myself that I actually wrote them and they were actually printed, bound, and read. I find that numbers of writers experience these same miseries over their work and do not, as is so often supposed, enjoy the process. "Creative joy" is something I haven't felt since I was fourteen and don't expect to feel again.”

With regard to the content of her writing, White remarked, “My novels and short stories are mainly about ordinary people who become involved in rather extraordinary situations. I do not mean in sensational adventures but in rather odd and difficult personal relationships largely due to their family background and their incomplete understanding of their own natures. I use both Catholic and non-Catholic characters and am particularly interested in the conflicts that arise between them and in the influences they have on each other.” Two of the main themes in White’s novels are her relationship with her father and her Catholic faith.

Recent years have seen a renewed critical interest in White's work. There are elements of her work that would associate her with modernism but she does not seem to be widely canonized.

In the introduction to Frost in May, Elizabeth Bowen describes the novel as a school story. She comments that the novel is written for adult readers, but that the language is comprehensible to an intelligent child of twelve. She writes, “We have Nanda’s arrival at Lippington, first impressions, subsequent adaptations, apparent success and, finally, head-on crash.” This plot deviates from what Bowen refers to as the normal school story only in that it does not have a happy ending. Frost in May was written during the rise of anti-school school stories after World War I.

With regard to her writing style, Bowen writes, “Antonia White’s style as a story-teller is as precise, clear and unweighty as Jane Austen’s. Without a lapse from this style Antonia White traverses passages of which the only analogy is to be found in Joyce’s Portrait of the Artist as a Young Man.” This comparison suggests that White’s writing is both reminiscent of 19th century realism and indicative of modernist tendencies.

Antonia White is the mother of Susan Chitty (another author), and Lyndall Passerini is the half-sister of Susan Chitty.