He was the second son of Ronald Leslie-Melville, 11th Earl of Leven and the former Emma Selina Portman (1863–1941).
[3] His father was a very wealthy landowner and resided at Holyrood Palace when he was Lord High Commissioner of Scotland.
He donated his collection of nineteenth century drawings and water-colours, which include scenes from Great Britain and Italy, to the Bodleian Library in 1920.
[9] On 3 September 1918, Lord Leven married, his half-cousin once removed, Lady Rosamond Sylvia Diana Mary Foljambe, a younger daughter of Cecil Foljambe, 1st Earl of Liverpool,[10] and, his second wife, Susan Louisa Cavendish (eldest daughter of Lt.-Col. William Henry Frederick Cavendish, a grandson of the 1st Earl of Burlington).
Together, they had five children:[5] Lord Leven died on 15 January 1947 and was succeeded by his 22 year old son, Alexander.