John Beaufort, Marquess of Dorset, Earl of Dorset (c. 1455 – 4 May 1471) was a scion of the Beaufort family, who fought for the Lancastrians in the Wars of the Roses.
He was the third son of Edmund Beaufort, 2nd Duke of Somerset and his wife, Lady Eleanor Beauchamp, daughter of Richard de Beauchamp, Earl of Warwick. When his eldest brother, Henry Beaufort, 3rd Duke of Somerset, was killed fighting for Lancaster in 1464 at the Battle of Hexham, the next brother, Edmund, succeeded to the Dukedom, and John became "Marquess of Dorset" and "Earl of Dorset", courtesy titles granted to the Beaufort heir-apparent or heir-presumptive. These titles were not recognized by King Edward IV, of the House of York. John had been in exile since 1461, first in Burgundy and then France. When Henry VI of Lancaster reclaimed the throne in early 1471, John returned with his brother Edmund. But almost at once, Henry was driven from the throne again, and the Lancastrians were on the run.
John was killed in the Battle of Tewkesbury on 4 May 1471, while fighting beside Edmund, who was captured and beheaded two days later. John was probably only sixteen years old when he died. He left behind no issue and was never married. With the death of John and Edmund, the legitimate male line of the Beauforts ended.