" The first recorded use to date of OMG is from 1917, and reads in full “I hear that a new order of Knighthood is on the tapis—O.M.G. (Oh! My God!)—Shower it on the Admiralty!” The citation comes from a letter by one John Arbuthnot Fisher, who happens to have been the admiral in charge of the British navy (a position known as first sea lord), and was written to Winston Churchill, staunch defender of both the English people and their language. "
― Ammon Shea , Bad English: A History of Linguistic Aggravation