Samuel Moor Shoemaker III DD, STD (December 27, 1893 – October 31, 1963) was an American priest in the Episcopal Church and a founding influence of Alcoholics Anonymous.

Samuel Shoemaker was considered one of the best preachers of his era, whose sermons were syndicated for distribution by tape and radio networks for decades. He founded Faith At Work magazine in 1926. He served as the rector of Calvary Episcopal Church in New York City from 1925 to 1952. He was the head of the United States headquarters of the Oxford Group (founded by Frank Buchman, who had a deep influence on him) and later of the Moral Re-Armament which the Oxford Group became in 1938, from circa 1927 until circa 1941. From 1952 to 1962, he served as the rector of Calvary Episcopal Church in Pittsburgh, Pennsylvania. He retired in 1962 and died the following year. Sam Shoemaker's interdenominational focus and the Oxford Group were significant influences for the founders of Alcoholics Anonymous (AA) who met through the Oxford Group. Bill Wilson attended Oxford Group meetings at Calvary Church from late 1934 to circa 1939. Sam Shoemaker helped start an Oxford Group chapter in Akron, Ohio, where Dr. Bob Smith became involved.

Serious disagreements with Oxford Group founder Frank Buchman led Shoemaker to separate from Buchman in 1941 after he had detached from the early AA for a while, before working with AA again later on.

Shoemaker's contributions and service to Alcoholics Anonymous had a worldwide effect. The program that Bill W. codified, in conjunction with Shoemaker, is used in almost every country around the world to not only treat alcoholism but also help relatives of alcoholics (Al-Anon/Alateen), and treat people suffering with other addictions such as drug addiction (Narcotics Anonymous, Cocaine Anonymous, Pills Anonymous, etc.), sex and love addiction (Sex and Love Addicts Anonymous) etc.

Shoemaker was born in a rented house on Read Street in Baltimore, Maryland on December 27, 1893, to Samuel Moor Shoemaker Jr. (later chairman of the Board of Regents of the University of Maryland) and Nellie Whitridge (later president of the Women's Auxiliary of the Episcopal Diocese of Maryland), who had met at Emmanuel Church in Baltimore, where his uncle was rector.

Two years later, in 1896, the young family moved to his late paternal grandfather's property, 'Burnside', about 10 miles north of Baltimore at the entrance to the Green Spring Valley. In 1898, his father turned Burnside into a dairy farm, with a prize herd of Guernsey cattle, though his grandfather had preferred Jerseys. Sam Shoemaker was well aware of his privileged upbringing: Mennonites, some Schumachers had moved from Germany, Holland and Switzerland hundreds of years earlier, converted to Quakerism under the influence of William Penn's missionaries and Anglicised their surname as they moved to Germantown, which became a Philadelphia neighborhood. One of his ancestors of the same name had twice served as Philadelphia's mayor, and his paternal grandfather (who died in 1884 and for whom both Sam's father and young Sam were named), although born in Lafourche Parish, Louisiana, made his fortune organizing the Great Western Express transportation line between Philadelphia and Baltimore. His paternal grandmother, the Victorian matriarch who raised him as an Episcopalian, was Augusta Chambers Eccleston, of Chestertown, Maryland, daughter of Maryland Court of Appeals Judge John Bowers Eccleston (1794–1860) and sister of the Rev. John H. E. Eccleston, whose Emmanuel Episcopal Church was decorated with flowers from the family's greenhouses. A more distant John C. Eccleston (1828–1912) served as a priest in Richmond County, New York. Sam's maternal grandfather, John Augustus Whitridge, had a fleet of clipper ships, although he died when Sam was 13. Shoemaker later became known for a slight southern inflection in his speech, which he attributed not to these relatives, but to his lifelong friend Hen Bodley, and to James (actually Richard Hugh Gwathney), a longtime family servant, who had been born in Fredericksburg, Virginia.

In 1908, when Sam was 14, he was sent to St. George's School, Rhode Island, an Episcopal boarding school founded and run by the Rev. John Byron Diman, who later converted to Roman Catholicism and founded the Portsmouth Priory near the school. Sam, homesick, initially did not feel comfortable among the "Yankees." He also did not consider himself a good student, but did hold several positions during his years at the school, including as president of the missionary society.

Upon graduating in 1912, Shoemaker attended Princeton University as had his father. A fan of President Woodrow Wilson, Shoemaker became acquainted with the political controversies of the day, and after his sophomore year, circa 1914, traveled to Europe. Upon returning, Shoemaker and three other students protested war propaganda and military drills at the university. At Princeton, Shoemaker had met Robert Speer, John Mott and Sherwood Eddy through the World Student Christian Federation. He became interested in personal evangelism and missionary work, as well as the relatively new ecumenical movement. He graduated from Princeton in 1916.