Catharine Maria Sedgwick (December 28, 1789 – July 31, 1867) was an American novelist of domestic fiction. From the 1820s to the 1850s, Sedgwick made a living writing short stories for a variety of periodicals. She became one of the most notable female novelists of her time. She wrote work in American settings, and combined patriotism with protests against historic Puritan oppressiveness. Her topics contributed to the creation of a national literature, enhanced by her detailed descriptions of nature. Sedgwick created spirited heroines who did not conform to the stereotypical conduct of women at the time. She promoted Republican motherhood.

Catharine Maria Sedgwick was born December 28, 1789, in Stockbridge, Massachusetts. Her mother was Pamela Dwight (1752–1807) of the New England Dwight family, daughter of General Joseph Dwight (1703–1765) and granddaughter of Ephraim Williams, founder of Williams College. Her father was Theodore Sedgwick (1746–1813), a prosperous lawyer and successful politician. He was later elected Speaker of the United States House of Representatives and in 1802, was appointed a justice of the Massachusetts Supreme Judicial Court.

Sedgwick's four brothers were educated for the law: they naturally followed the profession in which their father, Judge Sedgwick, had been eminent, yet only one of them followed him in the political career in which he had been equally distinguished. The eldest, Theodore, practiced law in Albany, New York and later served in the Massachusetts House of Representatives; Harry and Robert practiced law in New York; Charles, the youngest, practiced in Stockbridge. Her talents seem to have been appreciated by her brothers, Henry and Theodore, whose encouragement was acknowledged in the preface to a new edition of her works in 1849.

As a child, Sedgwick was cared for by Elizabeth Freeman (aka Mumbet), a former slave whose freedom Theodore Sedgwick helped gain by arguing her case in county court in 1781. After winning her freedom Freeman declined her previous owner's job offer, and instead accepted a job working for the Sedgwick family.

In her autobiography, Sedgwick refers to Elizabeth Freeman multiple times and reflects upon the influence Freeman had on Sedgwick's perception of the world. The integrity and pride that Freeman possessed regarding her own personal intelligence and understanding of the world can be reflected in Sedgwick's admiration of the woman.

When Sedgwick was seven or eight, she passed the summer under the care of her cousin Sabrina Parsons in Bennington, Vermont, at the house of the Rev. Mr. Swift, the husband of Sedgwick's aunt. At home, she attended the district schools, but no one dictated her studies or overlooked her progress. Reading, spelling, and Dwight's Geography were the only subjects taught, in addition to the first four rules of arithmetic, and the names of the several parts of speech. During her first winter in New York, when she was 11 years old, she studied dance under M. Lalliet, and had a French master who came three times a week. About two years later, she attended Mrs. Bell's boarding school in Albany, New York, as a day-scholar. At the age of 15, she was sent to Mr. Payne's boarding school in Boston to complete her education, and was there for six months. One of her schoolmates, Susan Anne Ridley Sedgwick (1788–1867), would become her sister-in-law and a published author.

As a young woman, Sedgwick took charge of a school in Lenox. She converted from Calvinism to Unitarianism, which led her to write a pamphlet denouncing religious intolerance. This further inspired her to write her first novel, A New-England Tale. Redwood followed in 1824. It was well received, and caused Sedgwick's name to be associated, and on equal terms, with that of James Fenimore Cooper, who was then at the height of his popularity. In a French translation of the book, Cooper is given on the title-page as the author. Redwood was also translated into the Italian, besides being reprinted in England.

In 1825, Sedgwick published The Travellers, a narrative of a journey made by two very young persons, a brother and sister, with their parents, to Niagara Falls and the northern lakes. On their way, these travelers meet everywhere some incident or some sight, which is made the source of entertainment and instruction. This was the first of Sedgwick's books intended for young persons and the public gave it a ready welcome. Its success encouraged her in after years to write the series of works intended for young readers which became popular.