William Graham, 3rd Earl of Menteith (c. 1500 – c. 1543) was a Scottish magnate and third Earl of Menteith.
He was the son of Alexander Graham, 2nd Earl of Menteith (c. 1475 – c. 1537), and Margaret Buchanan. He was the great-grandson of Malise Graham, 1st Earl of Menteith (1406–1490). In 1521 he married Margaret Moubray, daughter of John Moubray of Barnbougle (she had previously been married to John Cornwall before his death in 1513), and they had five sons and two daughters, including:
On 20 May 1527, when he was titled Master of Menteith, he ran away from the King's army at Solway, but was pardoned despite it being considered an act of treason. He became the third Earl, receiving sasine of the Earldom on 16 May 1537. After the death of King James V in 1542, William was an opponent of the English interest in Scotland and on 24 July 1543 he signed a bond made by Cardinal Beaton to stop King Henry VIII of England from getting possession of the infant Mary, Queen of Scots.
William Graham was killed in a clan fight some time in autumn 1543, but certainly by 23 January 1544; some sources state that he was killed in October 1543 by the Tutor of Appin (a member of the Stewart family), after the Stewarts and their army ate a wedding feast to which the Earl had been invited. Some accounts also tell of the Murrays of Athole being the raiders of the feast. According to most stories, a band of Stewarts were passing through Menteith and happened upon a wedding feast. They ate up all the food, drank all the wine, and left within a short while. The Earl pursued them and was slain or mortally wounded by the robbers. Historian Andrew Fleming Hutchison recorded the colorful details this way: