He was born Walter Johnston in 1863 in Kingstown (now Dún Laoghaire), County Dublin, Ireland.[2] He later changed his name by deed poll to Edgeworth-Johnstone. In 1895 and 1896 he was Amateur Boxing Association of England heavyweight champion. He was also an excellent footballer and cricket player, and won numerous titles in fencing,[3] including the sabre title at the 1898 and 1900 British Fencing Championships.[4]
He was commissioned a lieutenant in the Royal Irish Regiment on 25 August 1886, and promoted to captain on 5 April 1893. In February 1900 he was appointed to act temporarily as assistant inspector of gymnasia at Aldershot.[5][6] He transferred to the Curragh Camp where he was superintendent of gymnasia from 5 February 1901 to 30 September 1902.[7] He returned to his regiment in January 1903.[8]
Edgeworth-Johnstone was chief commissioner of the Dublin Metropolitan Police from 1915 to 1923.[1] The unarmed Dublin Metropolitan Police stayed largely neutral during the Irish War of Independence.
Edgeworth-Johnstone was named a companion of the Order of the Bath in the 1918 New Year Honours. He was invested as a Knight Commander of the Order of the British Empire in 1924, and promoted to lieutenant-colonel.[1]
In 1897, Edgeworth-Johnstone married Helen Gunning Walker Waters. They had two sons and two daughters. One of his sons was Robert Edgeworth-Johnstone, a chemical engineer. Walter Edgeworth-Johnstone died 4 January 1936 in Regent's Park Terrace, London.[3]
