Admiral Sir Lionel Halsey, GCMG, GCVO, KCIE, CB, ADC (26 February 1872 – 26 October 1949) was a Royal Navy officer and courtier.

[7] From October 1902, he served as Executive Officer and second in command of HMS Good Hope,[8] which was the following month commissioned to convey Joseph Chamberlain, Secretary of State for the Colonies, on his tour of South Africa in late 1902 and early 1903.

[18] He was present at the Battle of Jutland, being mentioned in despatches[19] for a third time and appointed a Companion of the Order of the Bath (CB) on 3 June 1916 (in the King's Birthday Honours).

[29] In September 1918, he returned to sea in the battle cruiser HMAS Australia in command of the 2nd Battlecruiser Squadron of the Grand Fleet and was present at the German surrender at Scapa Flow.

[30] He served at the Admiralty from March to August 1919, when he became chief of staff to the Prince of Wales for his tour of Canada, the United States, Australia, New Zealand, the West Indies, and other colonies in HMS Renown.

He was appointed a Knight Commander of the Order of the Indian Empire (KCIE) in 1922 after the Prince's visit to India, advanced to Knight Grand Cross of the Order of St Michael and St George (GCMG) on 16 October 1925 following the Prince's visit to Africa and South America,[37] and promoted admiral on 4 October 1926.

In 1937, however, he was appointed an extra equerry to the new King George VI[41][42] and took part in the coronation procession as acting Keeper of the Jewel House.