Kate was the third of five children, but her sisters died in infancy and her half-brothers (from her father's first marriage) died in their early twenties. They were reared Roman Catholic, in the French and Irish traditions. After her father's death in 1855, Chopin developed a close relationship with her mother, maternal grandmother, and great-grandmother. She also became an avid reader of fairy tales, poetry, and religious allegories, as well as classic and contemporary novels. She graduated from Sacred Heart Convent in St. Louis in 1868.

In St. Louis, Missouri, on 8 June 1870, she married Oscar Chopin and settled with him in his home town of New Orleans, an important port. Chopin had six children between 1871 and 1879: in order of birth, Jean Baptiste, Oscar Charles, George Francis, Frederick, Felix Andrew, and Lélia (baptized Marie Laïza). In 1879, Oscar Chopin's cotton brokerage failed.

When Oscar Chopin died in 1882, he left Kate with $42,000 in debt (approximately $420,000 in 2009 money). According to Emily Toth, "for a while the widow Kate ran his [Oscar's] Business and flirted outrageously with local men; (she even engaged in a relationship with a married farmer)." Although Chopin worked to make her late husband's plantation and general store succeed, two years later she sold her Louisiana Business.

By the early 1890s, Kate Chopin began writing short stories, articles, and translations which were published in periodicals, including the St. Louis Post-Dispatch newspaper. She was quite successful and placed many of her publications in literary magazines. At the time, she was considered only as a regional local color Writer, as this was a period of considerable publishing of folk tales, works in dialect, and other elements of Southern folk life. Chopin's strong literary qualities were overlooked.

Of maternal French and paternal Irish descent, Chopin was born in St. Louis, Missouri. She married and moved with her husband to New Orleans. They later lived in the country in Cloutierville, Louisiana. From 1892 to 1895, Chopin wrote short stories for both children and adults that were published in such national magazines as Atlantic Monthly, Vogue, The Century Magazine, and The Youth's Companion. Her stories aroused controversy because of her subjects and her approach; they were condemned as immoral by some critics.

"Desiree's Baby" was first published in an 1893 issue of Vogue magazine, alongside another of Kate Chopin's short stories, "A Visit to Avoyelles", under the heading "Character Studies: The Father of Desiree's Baby - The Lover of Mentine." "A Visit to Avoyelles" typifies the local color writing that Chopin was known for, and is one of her stories that shows a couple in a completely fulfilled marriage. While Doudouce is hoping otherwise, he sees ample evidence that Mentine and Jules' marriage is a happy and fulfilling one, despite the poverty-stricken circumstances that they live in. In contrast, in "Desiree's Baby", which is much more controversial, due to the topic of miscegenation, portrays a marriage in trouble. The other contrasts to "A Visit to Avoyelles" are very clear, although some are more subtle than others. Unlike Mentine and Jules, Armand and Desiree are rich and own slaves and a plantation. Mentine and Jules' marriage has weathered many hard times, while Armand and Desiree's falls apart at the first sign of trouble. Kate Chopin was very talented at showing various sides of marriages and local people and their lives, making her writing very broad and sweeping in topic, even as she had many Common themes in her work.

Her major works were two short story collections: Bayou Folk (1894) and A Night in Acadie (1897). Her important short stories included "Désirée’s Baby" (1893), a tale of miscegenation in antebellum Louisiana, "The Story of an Hour" (1894), and "The Storm" (1898). "The Storm" is a sequel to "At the Cadian Ball," which appeared in her first collection of short stories, Bayou Folk.

In 1899, her second novel, The Awakening, was published. It generated a significant amount of negative press because its characters, especially the women, behaved in ways that conflicted with current standards of acceptable ladylike behavior. People considered offensive Chopin's treatment of female sexuality, her questions about the virtues of motherhood, and showing occasions of marital infidelity. At the same time, some newspaper critics reviewed it favorably.

Critics suggest that such works as The Awakening, were too far ahead of their time and therefore not socially embraced. After almost 12 years of publishing and shattered by the lack of acceptance, Chopin, deeply discouraged by the criticism, turned to short story writing. In 1900, she wrote "The Gentleman from New Orleans." That same year she was listed in the first edition of Marquis Who's Who. However, she never made much money from her writing, and had to depend on her Investments in Louisiana and St. Louis (aided by her inheritance from her mother) to support her.

While visiting the St. Louis World's Fair on August 20, 1904, Chopin suffered a brain hemorrhage. She died two days later, at the age of 54. She was interred in Calvary Cemetery in St. Louis.

Within a decade of her death, Chopin was widely recognized as one of the leading Writers of her time. In 1915, Fred Lewis Pattee wrote, "some of [Chopin's] work is equal to the best that has been produced in France or even in America. [She displayed] what may be described as a native aptitude for narration amounting almost to genius."

This, her best-known work, is the story of a woman trapped in the confines of an oppressive society. It was out of print for several decades, as literary tastes changed. Rediscovered in the 1970s, when there was a wave of new studies and appreciation of women's writings, the novel has since been reprinted and is widely available. It has been critically acclaimed for its writing quality and importance as an early feminist work of the South.

The short story of "Désirée's Baby" focuses on Kate Chopin's experience with miscegenation and communities of the Creoles of color in Louisiana. She came of age when slavery was institutionalized in St. Louis and the South. In Louisiana, there had been communities established of free people of color, especially in New Orleans, where formal arrangements were made between white men and free women of color or enslaved women for plaçage, a kind of common-law marriage. There and in the country, she lived with a society based on the history of slavery and the continuation of plantation life, to a great extent. Mixed-race people (also known as mulattos) were numerous in New Orleans and the South. This story addresses the racism of 19th century America; persons who were visibly European-American could be threatened by the revelation of also having African ancestry. Chopin was not afraid to address such issues, which were often suppressed and intentionally ignored. Her character Armand tries to deny this reality, when he refuses to believe that he is of black descent, as it threatens his ideas about himself and his status in life. R. R. Foy believed that Chopin's story reached the level of great fiction, in which the only true subject is "human existence in its subtle, complex, true meaning, stripped of the view with which ethical and conventional standards have draped it".