Joan Beaufort (c. 1404 – 15 July 1445) was the Queen Consort of Scotland from 1424 to 1437 as the spouse of King James I of Scotland. During part of the minority of her son James II (from 1437 to 1439), she served as the Regent of Scotland.
She was a daughter of John Beaufort, 1st Earl of Somerset, and Margaret Holland and half-niece of King Henry IV of England. Joan was named after her aunt, Joan Beaufort, Countess of Westmorland. James of Scotland fell in love with her during his time as a prisoner in England (1406–1424). She is said to have been the inspiration for James's famous long poem, The Kingis Quair, written in his captivity after he saw her from his window in the garden. The powerful Beauforts put pressure on Henry V to release him so they could get married. Queen Catherine also urged him to do so. Discussions were held, and it was decided that her dowry would be subtracted from his ransom.
On 2 February 1424 at Southwark Priory (now Southwark Cathedral), Joan married James I. They were feasted at Winchester Palace that year by her uncle Cardinal Henry Beaufort. She joined him on his return from captivity to Scotland that year. At his coronation at Scone, when James received the allegiance of his Tenants-in-chief, he had them swear their allegiance to Joan as well, as if she was a co-monarch. As queen, she often pleaded with the king for those who might be executed.
The royal couple had eight children, including the future James II, and Margaret of Scotland, spouse of Louis XI of France.
After James I was assassinated at the Dominican Friary in Perth in 1437, Joan took over the regency for her son: she had also been a target of assassination along with her husband, but escaped, injured, from the place where it happened. She took custody of her son, now James II, and assumed the regency. The prospect of being ruled by an English woman was unpopular and the Earl of Douglas was thus appointed co-regent. She held the side of Robert II's family responsible for murdering James I killed, protecting her and her son's position. She was Regent for two years. To avoid the dominance of William Crichton, Joan left Edinburgh for Stirling Castle and the protection of Alexander Livingston. When Crichton and Livingston made peace, she allied herself with Sir James Stewart, the Black Knight of Lorn.
On 21 September 1439, she married Stewart after obtaining a papal dispensation for both consanguinity and affinity. James was an ally of the latest Earl of Douglas, and plotted with him to overthrow Alexander Livingston, governor of Stirling Castle, during the minority of James II of Scotland. Livingston arrested Joan on 3 Aug 1439, imprisoned her in Stirling castle and threw James and his brother William into its dungeon. James and William were later released on parole. Joan was released after her resignation as regent. She died in 1445 and was buried alongside her husband in the Carthusian Priory at Perth, which he had founded. The royal tomb was destroyed, along with the other religious houses of Perth, at the time of the Scottish Reformation in 1559.