The Barons' Letter of 1301 was written by seven English earls and 96 English barons to Pope Boniface VIII as a repudiation of his claim of feudal overlordship of Scotland, and as a defence of the rights of King Edward I of England as overlord of Scotland. It was, however, never sent. The letter survives in two copies, known as A and B, both held in the National Archives at Kew under the reference E 26. Historically they were held amongst the documents in the Exchequer, Treasury of the Receipt department.

Pope Boniface VIII, born Benedetto Caetani was the head of the Catholic Church and ruler of the Papal States from 24 December 1294 until his death in 1303. The Caetani family was of baronial origin, with connections to the papacy. He succeeded Pope Celestine V, who had abdicated from the papal throne. Boniface spent his early career abroad in diplomatic roles.