Admiral of the Fleet Sir Rhoderick Robert McGrigor GCB (12 April 1893 – 3 December 1959) was a senior Royal Navy officer. He fought in the First World War and saw action during the Gallipoli Campaign and then the Battle of Jutland. He also served in the Second World War, taking part in the sinking of the "Bismarck" in May 1941, carrying out the office of Assistant Chief of the Naval Staff (Weapons) and commanding the 1st Cruiser Squadron during operations off the Norwegian coast and convoys to North Russia. Furthermore, he served as First Sea Lord in the early 1950s and is most remembered as a leading proponent of carrier-based air power.