This name was on the original memorial in St Werburgh’s, but not on the Town Hall Memorial, nor St Francis. There does not appear to be an O'Leary family who are parishioners of St Werburgh's around this time. The possibilities from Commonwealth War Graves Commission records are as follows:
O'LEARY, PATRICK
Rank: Private
Service No: 3207
Date of Death: 24/09/1916
Age: 25
Regiment/Service: King's Own Yorkshire Light Infantry, 1st/4th Btn
Grave Reference: XI. A. 14A.
Cemetery: ETAPLES MILITARY CEMETERY
Additional Information: Son of Michael and Johanna O'Leary, of Ballybeg, Farranfore, Co. Kerry.
O'LEARY, PATRICK
Rank: Private
Service No: 21466
Date of Death: 28/06/1916
Age: 40
Regiment/Service: Lancashire Fusiliers, 1st Btn
Grave Reference: II. B. 17.
Cemetery: AUCHONVILLERS MILITARY CEMETERY
Additional Information: Son of Michael and Ellen O'Leary, of Kilmanor, Ireland; husband of Bridget O'Leary, of 296, Tarrent Terrace, Godregraig, Glam. Born at Rawalpindi, India.
O'LEARY, JOHN PATRICK
Rank: Private
Service No: 11180
Date of Death: 17/08/1916
Age: 37
Regiment/Service: Duke of Cornwall's Light Infantry, 'C' Coy. 7th Btn.
Grave Reference: Near North-West corner.
Cemetery: MONDICOURT COMMUNAL CEMETERY
Additional Information: Husband of Eleanor O'Leary, of 80, 'C' Block, Guinness Buildings, Vauxhall, London.
O'LEARY, ROBERT PATRICK
Rank: Private
Service No: 13655
Date of Death: 02/10/1918
Age: 24
Regiment/Service: The Loyal North Lancashire Regiment, 1st Btn.
Panel Reference: Panel 7.
Memorial: VIS-EN-ARTOIS MEMORIAL
Additional Information: Son of Michael and Anastasia O'Leary, of 5, Chaucer Place, Liverpool.
There is no way of knowing which, if any, of these men was the one whose name was inscribed on the original St Werburgh's Great War Memorial Plaque.