The monarch of Scotland was the head of state of the Kingdom of Scotland. According to tradition, the first King of Scots was Kenneth I MacAlpin (Cined mac Ailpn), who founded the state in 843. Historically, the Kingdom of Scotland is thought to have grown out of an earlier "Kingdom of the Picts" (and later the Kingdom of Strathclyde that was conquered in the 11th century, becoming part of the new Kingdom of Scotland) though in reality the distinction is a product of later medieval myth and confusion from a change in nomenclature i.e. Rex Pictorum ('King of the Picts') becomes R Alban (King of Alba) under Donald II when annals switched from Latin to vernacular around the end of the 9th century, by which time the word Alba in Scottish Gaelic had come to refer to the Kingdom of the Picts rather than Britain (its older meaning).The Kingdom of the Picts just became known as the Kingdom of Alba in Scottish Gaelic, which later became known in Scots and English as Scotland; the terms are retained in both languages to this day. By the late 11th century at the very latest, Scottish kings were using the term rex Scottorum, or King of Scots, to refer to themselves in Latin. The Kingdom of Scotland was merged with the Kingdom of England to form a single Kingdom of Great Britain in 1707. Thus, Queen Anne became the last monarch of the ancient kingdoms of Scotland and England and the first of Great Britain, although the kingdoms had shared a monarch since 1603 (see Union of the Crowns). Her uncle Charles II was the last monarch to be crowned in Scotland, at Scone in 1651. He had a second coronation in England ten years later.

Mary, Queen of Scots (8 December 1542 – 8 February 1587), also known as Mary Stuart or Mary I of Scotland, was Queen of Scotland from 14 December 1542 until her forced abdication in 1567.

The only surviving legitimate child of James V of Scotland, Mary was six days old when her father died and she acceded to the throne. During her childhood, Scotland was governed by regents, first by the heir to the throne, James Hamilton, Earl of Arran, and then by her mother, Mary of Guise. In 1548, she was betrothed to Francis, the Dauphin of France, and was sent to be brought up in France, where she would be safe from invading English forces during the Rough Wooing. Mary married Francis in 1558, becoming queen consort of France from his accession in 1559 until his death in December 1560. Widowed, Mary returned to Scotland in August 1561. Following the Scottish Reformation, the tense religious and political climate that Mary encountered on her return to Scotland was further agitated by prominent Scots such as John Knox, who openly questioned whether her subjects had a duty to obey her. The early years of her personal rule were marked by pragmatism, tolerance, and moderation. She issued a proclamation accepting the religious settlement in Scotland as she had found it upon her return, retained advisers such as James Stewart, Earl of Moray, and William Maitland of Lethington, and governed as the Catholic monarch of a Protestant kingdom.

Mary married her half-cousin, Henry Stuart, Lord Darnley, in 1565, and in June 1566, they had a son, James. In February 1567, Darnley's residence was destroyed by an explosion, and he was found murdered in the garden. James Hepburn, 4th Earl of Bothwell, was generally believed to have orchestrated Darnley's death, but he was acquitted of the charge in April 1567, and the following month, he married Mary. Following an uprising against the couple, Mary was imprisoned in Loch Leven Castle. On 24 July 1567, she was forced to abdicate in favour of her one-year-old son. After an unsuccessful attempt to regain the throne, she fled southward seeking the protection of her first cousin once removed, Elizabeth I of England. (Elizabeth was the granddaughter of Henry VII of England, and Mary was his great-granddaughter.)

Mary had once claimed Elizabeth's throne as her own and was considered the legitimate sovereign of England by many English Catholics, including participants in a rebellion known as the Rising of the North. Perceiving Mary as a threat, Elizabeth had her confined in various castles and manor houses in the interior of England. After eighteen and a half years in captivity, Mary was found guilty of plotting to assassinate Elizabeth in 1586 and was beheaded the following year at Fotheringhay Castle. Mary's life, marriages, lineage, alleged involvement in plots against Elizabeth, and subsequent execution established her as a divisive and highly romanticised historical character, depicted in culture for centuries.