Ogilvie Blair Graham, DSO, OBE, TD (8 July 1891 – 30 May 1971) was an Irish first-class cricketer and British Army officer. Graham served with the Oxford University Officers' Training Corps before receiving a commission in the Rifle Brigade. During the First World War he rose to command a battalion of the Rifles and received the Distinguished Service Order. Graham was later an instructor in infantry tactics, before transferring to the Royal Artillery (RA) in the Territorial Army. During the Second World War he commanded the RA defences in Northern Ireland and was appointed an officer of the Order of the British Empire. He also served as a deputy lieutenant and High Sheriff of County Down. Graham played cricket for Harrow School and later made first-class appearances for Oxford University,