Harold Rupert Leofric George Alexander, 1st Earl Alexander of Tunis, KG, GCB, OM, GCMG, CSI, DSO, MC, CD, PC (Can), PC (10 December 1891 – 16 June 1969) was a senior British Army officer who served with distinction in both the First and the Second World War and, afterwards, as Governor General of Canada and the first Lord Lieutenant of Greater London in 1965.