American writer, noted for short stories that reveal her elevated sensibilities and fine craftsmanship.

Katharine Fullerton was of staunchly New England lineage for many generations on either side. She was schooled privately in Boston and France, graduated from Radcliffe College in Cambridge, Massachusetts, in 1900, took a master's degree in 1901, and taught English and writing at Bryn Mawr (Pennsylvania) College from 1901 until her marriage in June 1910 to Gordon H. Gerould, a Princeton professor.

In 1900 she had won a prize from Century magazine for the best short story by an undergraduate for “The Poppies in the Wheat,” which showed the strong influence of Henry James (James, Henry). Her second story, “Vain Oblations,” was written while on leave from Bryn Mawr in 1908–09; during that leave she traveled to England and met James. Her later short stories, generally moral dilemmas spun from the confrontation of well-bred protagonists with exotic locales and temptations, reflected the influences of Joseph Conrad (Conrad, Joseph) and Rudyard Kipling (Kipling, Rudyard), among others. Published mainly in Atlantic Monthly, Harper's, and Scribner's, many of her stories were collected in Vain Oblations (1914), The Great Tradition (1915), and Valiant Dust (1922).

Critically well received and frequently anthologized, Gerould's stories were marked by a refined and somewhat detached style and subtle insight. Her novels, A Change of Air (1917), Lost Valley (1922), Conquistador (1923), and The Light That Never Was (1931), were less successful. She achieved greater success—but stirred widespread controversy among critics and journals of opinion—with her essays. Her literary criticism tended to be narrow, and her essays on social and political topics revealed a marked distaste for democratic manifestations in art, manners, and public affairs. She stoutly defended a traditional hierarchical order of society, spiritual over material values, and the superiority of breeding to training. Collections of her essays appeared as Modes and Morals (1920) and Ringside Seats (1937). She also published two volumes of travel sketches, Hawaii: Scenes and Impressions (1916) and The Aristocratic West (1925).