Mervyn Edward Wingfield, 7th Viscount Powerscourt KP PC (Ire) (13 October 1836 – 5 June 1904) was an Irish peer.

Through this Wingfield line he was a maternal descendant of the Noble House of Stratford.

His mother was Lady Elizabeth Frances Charlotte, daughter of Robert Jocelyn, 3rd Earl of Roden.

They had five children:[1] He was commissioned as a Lieutenant in the part-time Wicklow Militia on 26 November 1870, promoted to Captain on 31 March 1871, and retired on 12 October 1871.

[3] He was created Baron Powerscourt in the Peerage of the United Kingdom in 1885, enabling him to sit in the House of Lords.