William George Montagu Hay, 11th Marquess of Tweeddale JP (4 November 1884 – 30 March 1967) was a Scottish aristocrat, land owner and soldier.
His uncle, Arthur Hay, 9th Marquess of Tweeddale, was married to Julia Mackenzie, and after his death, she remarried to Sir John Rose, 1st Baronet and William Evans-Gordon, MP.
[7] His maternal grandfather was from Cantiano in Marche, Italy and an aunt, Evelyn Bartolucci, was the second wife of Adm. Sir Astley Cooper Key.
[10] Together, William and Marguerite were the parents of:[8] After the death of his first wife on 15 October 1944,[15] Lord Tweeddale remarried to Marjorie Helen (née Wagg) Nettlefold on 24 March 1945.
His only son died before him, so he was succeeded in his titles by his nephew, David George Montagu Hay, who became the 12th Marquess of Tweeddale.