Brigadier-General Sir George William Hacket Pain KBE CB (5 February 1855 – 14 February 1924) was a British Army officer and Royal Irish Constabulary commissioner. He played a key part in setting up the Ulster Volunteers as a unionist militia during the Home Rule crisis of 1912, and was believed to have organised gun-running. At the outbreak of the First World War he served in command of a Brigade of the Ulster Division and commanding British forces in the north of Ireland. He served briefly as a Unionist Member of Parliament.