John Vesey, 6th Viscount de Vesci

Lady de Vesci died from cancer three years after her husband, in May 1986.

He lived at Abbey Leix House on the River Nore in County Laois. In 1967, he sold the De Vesci Collection that was housed at Abbey Leix House to the National Library of Australia. This acquisition added 1648 books (about 2900 volumes) and 54 serials (about 390 volumes) to the National Library of Australia.

Miss Catherine Vesey was one of the bridesmaids at the wedding of Princess Margaret and Antony Armstrong-Jones on 24 March 1960.

He was the son of Lt. Col. Hon. Thomas Eustace Vesey and Lady Cecily Kathleen Browne, daughter of Valentine Browne, 5th Earl of Kenmare. He became the Viscount de Vesci of Abbey Leix on 16 August 1958. He succeeded his paternal uncle, the 5th Viscount, who was survived by his widow, Lois (daughter of Sir Cecil Edmund Lister-Kaye, 4th Bt., and widow a first time of the 5th Earl of Rosse and mother of the 6th Earl of Rosse). He was the great-grandson of Thomas Vesey, 3rd Viscount de Vesci. His father was an Eton and Oxford-educated Lieutenant Colonel in the Irish Guards who fought and was wounded twice in the First World War. He himself was also in the Irish Guards, fighting in the Second World War and being captured.

He was the brother-in-law of Antony Armstrong-Jones, 1st Earl of Snowdon, having married Snowdon's older sister, Susan Anne Armstrong-Jones, on 20 May 1950. She was the daughter of barrister Ronald Armstrong-Jones and of Anne Parsons, Countess of Rosse. When she married Lord de Vesci, she converted to Catholicism. Her wedding dress was designed by her mother. The reception was held at the home of her paternal grandmother, Lady Armstrong-Jones, in Lancaster Gate.

John Eustace Vesey, 6th Viscount de Vesci (25 February 1919 – 13 October 1983), was an Irish peer.

He was the 8th baronet of the Vesey of Abbey Leix, which baronetcy was created on 28 September 1698.