Dockrell, George Shannon (1886–1924), swimmer and water-polo player, was born 22 October 1886 in Rathdown, Co. Dublin, the son of Sir Maurice Edward Dockrell (qv), merchant and politician, and his wife Margaret Sarah Dockrell (qv) (née Shannon). He was a member of a prominent swimming family – both his brother, Henry Morgan Dockrell (qv), and cousin won Irish swimming championships, and his brother was also a water-polo player at international level. Dockrell was affiliated with the Dublin University swimming club. From 1904, when he won the Irish 100 and 440 yards championships, until his retirement in 1911 he was the dominant figure in Irish swimming. In October 1905 he travelled to New York, where he joined the New York Athletic Club. He started to train with the foremost American swimmers, including C. M. Daniels, then the fastest 100 yard swimmer in the world. Having trained for six months Dockrell came third in the US 440 and 880 yards championships. On his return to Ireland in 1906 he won all the main swimming championships of that year.
The London Olympic games in 1908 confirmed Dockrell's pre-eminence in British swimming when he was the only member of the team to reach the semi-finals of the 100 yards; he only narrowly missed winning a place in the four-man final. Later that year he came third in the 220 yard world championship in Nottingham. On 16 August 1909 he finished first in the 100 metres world championship in Paris, beating Vasseur of France, though this victory was somewhat devalued by the absence of the Olympic medalists of 1908 from the competition. After recording a new Irish record of 58.6 seconds in the 100 yard Irish championship of 1911 he retired. In all he won twenty of the twenty-seven Irish championship events he entered, and held the Irish records in three events. He also won seven international caps at water polo.
Dockrell served as a major in the army in the first world war and received an OBE for bravery. While serving with the rifle brigade in France he was severely wounded in combat; he later died of his wounds at the Officers’ Hospital in Richmond, Surrey, on 23 December 1924.