expatriate American writer whose best-selling fiction observed European and American cultural differences.

Sedgwick lived from the age of nine in London, where her father had business connections. In 1898 a novel she had written for private amusement was, through her father's efforts, published in London as The Dull Miss Archinard. The success of that book led her to produce in rapid order The Confounding of Camelia (1899), The Rescue (1902), Paths of Judgment (1904), The Shadow of Life (1907), A Fountain Sealed (1907), Anabel Channice (1908), and Franklin Winslow Kane (1910). Writing in much the same vein as Edith Wharton (Wharton, Edith) and Henry James (James, Henry), Sedgwick contrasted the mores and morals of American and European cultures. Tante (1911), her first major success, was a best-seller in the United States. The Nest, a collection of stories (1912), and The Encounter (1914) followed.

During World War I Sedgwick and her husband, the essayist Basil de Sélincourt (whom she had married in 1908), worked in hospitals and orphanages in France. After the war Sedgwick resumed her writing, producing a nonfiction work, A Childhood in Brittany Eighty Years Ago (1919), as well as several stories and novels, including The Little French Girl (1924), another best-seller. In 1931, during her last visit to the United States, she was elected to the National Institute of Arts and Letters.