Mervyn Niall Wingfield was born in 1935, son of Mervyn Patrick Wingfield, 9th Viscount Powerscourt (1905–1973) and the former Sheila Claude Beddington.
He succeeded his father in the family honours on 3 April 1973.
[1] He married Wendy Anne Pauline Slazenger, daughter of Ralph C.G.
On 15 March 1978, he married Pauline Vann, a Californian; they were divorced in 1995.
He died on 25 July 2015, in Thailand, where he had been living for some time.