O'Kelly de Gallagh et Tycooly, Gerald Edward (1890–1968), diplomat, was born 11 March 1890 at Gurtray, Portumna, Co. Galway, third among seven sons of Count John Appleyard O'Kelly – his ancestor Festus O'Kelly de Gallagh et Tycooly had been created a count of the Holy Roman Empire in 1767 by the empress Maria Theresa of Austria – and his wife Mary (daughter of Count John O'Byrne of Corville and granddaughter of Baron von Hubner, Austrian ambassador in Paris 1849–58).
He was educated at Clongowes Wood College, Co Kildare, and matriculated for the RUI. After traveling extensively in the Far East and America, he saw active service in the first world war from 1915 and was wounded in action. Arthur Griffith (qv) appointed O'Kelly Irish agent to Switzerland in July 1919. That year he was also active in the Irish delegation to the Paris peace conference. He remained Dáil Éireann representative to Switzerland until March 1921, and was Ireland's unofficial diplomatic agent in Brussels from April 1921 to 1923. He held the official appointment of Irish trade agent to Belgium from 1923 to September 1929.
In September 1929 he was appointed as the Irish Free State's first envoy extraordinary and minister plenipotentiary to France, and from 1931 minister (non-resident) to Belgium; he held the Paris post to 1935. O'Kelly had excellent connections in the Paris social scene, which he put to use during his diplomatic career. This was particularly so during the 1929–30 canvass for the successful Irish bid for a temporary seat on the League of Nations council in 1930, when O'Kelly visited almost every diplomatic mission in Paris to gain support for the Irish candidature.
On 1 June 1935 O'Kelly was instructed to report back to Dublin for duty at headquarters. He was replaced in Paris as minister by Art O'Brien (qv), a relatively ineffectual diplomat who had been reinstated in the diplomatic service in 1932. In October 1935 O'Kelly officially retired from the Irish diplomatic service, but was appointed special counsellor to the Irish legations in Paris and Brussels. He was the sole Irish diplomat to remain in Paris throughout the second world war, and was responsible for negotiating the release of many Irish citizens interned by the Germans. From the mid 1930s he also operated a wine business in France. He returned to the diplomatic service in 1948 as chargé d'affaires in Lisbon, with the personal rank of minister; he again retired in August 1955, but remained in service as honorary counsellor to the Irish legation in Lisbon. In 1962 he was again invited by the Irish government to take up the post of chargé d'affaires at Lisbon, in which position he remained in Portugal until his death.
O'Kelly was a collector and connoisseur of old prints and translated the poetry of Omar Khayyám and the writings of Marco Polo into French. In addition to being a count of the Holy Roman Empire, he was a Knight of the Sovereign Order of Malta, a Grand Officer of the Légion d'honneur, and a Grand Officer of the Order of Christ. He married (1920) Amy Marjorie (d. 18 December 1957), daughter of John Stuart of Liverpool; they had no children. He died in Lisbon 3 January 1968 and was buried there, with his wife, on 5 January.