Sir Thomas More (7 February 1478 – 6 July 1535), venerated in the Catholic Church as Saint Thomas More, was an English lawyer, judge, social philosopher, author, statesman, theologian, and noted Renaissance humanist. He also served Henry VIII as Lord Chancellor from October 1529 to May 1532. He wrote Utopia, published in 1516, which describes the political system of an imaginary island state.

More opposed the Protestant Reformation, directing polemics against the theology of Martin Luther, Huldrych Zwingli and William Tyndale. More also opposed Henry VIII's separation from the Catholic Church, refusing to acknowledge Henry as supreme head of the Church of England and the annulment of his marriage to Catherine of Aragon. After refusing to take the Oath of Supremacy, he was convicted of treason on what he stated was false evidence, and was executed. At his execution, he was reported to have said: "I die the King's good servant, and God's first."

Pope Pius XI canonised More in 1935 as a martyr. Pope John Paul II in 2000 declared him the patron saint of statesmen and politicians. In his proclamation the pope stated: "It can be said that he demonstrated in a singular way the value of a moral conscience ... even if, in his actions against heretics, he reflected the limits of the culture of his time".

Born in the City of London, on 7 February 1478, Thomas More was the son of Sir John More (a successful lawyer and later a judge) and his wife Agnes (née Graunger). John More lived most of his life in Milk Street, London and, from this, many biographers (starting in the seventeenth century with More's great-grandson Cresacre More (1572–1649), the youngest son and eventual heir of Thomas More II) have asserted, without confirmation, that this was the place of Thomas More's birth. No contemporary biographer recorded this. He was the second of six children. More was educated at St. Anthony's School, then considered one of London's best schools. From 1490 to 1492, More served John Morton, the Archbishop of Canterbury and Lord Chancellor of England, as a household page.

Morton enthusiastically supported the "New Learning" (scholarship which was later known as "humanism" or "London humanism"), and thought highly of the young More. Believing that More had great potential, Morton nominated him for a place at the University of Oxford, either in St. Mary Hall or Canterbury College, both now defunct.

More began his studies at Oxford in 1492. He received a classical education studying under Thomas Linacre and William Grocyn, and he became proficient in both Latin and Greek. More left Oxford after only two years—at his father's insistence—to begin legal training in London at New Inn, one of the Inns of Chancery. In 1496, More became a student at Lincoln's Inn, one of the Inns of Court, where he remained until 1502, when he was called to the bar.

A noted linguist, More could speak and banter in Latin with the same facility as in English, and had competency in Greek and several other languages. He wrote and translated poetry. He was particularly influenced by Pico della Mirandola and translated the Life of Pico into English.

According to his friend, the theologian Desiderius Erasmus of Rotterdam, More once seriously contemplated abandoning his legal career to become a monk. Between 1503 and 1504 More lived near the Carthusian monastery outside the walls of London and joined in the monks' spiritual exercises. Although he deeply admired their piety, More ultimately decided to remain a layman, standing for election to Parliament in 1504 and marrying the following year.