| Bedfordshire | 0 |
| Buckinghamshire | 0 |
| Berkshire | 0 |
| Cambridgeshire | 0 |
| Channel Islands | 0 |
| Cheshire | 0 |
| Cornwall | 0 |
| Cumberland | 0 |
| Derbyshire | 0 |
| Devon | 0 |
| Dorset | 0 |
| Durham | 0 |
| Essex | 0 |
| Gloucestershire | 0 |
| Hampshire | 0 |
| Herefordshire | 0 |
| Hertfordshire | 0 |
| Huntingdonshire | 0 |
| Isle of Man | 0 |
| Kent | 0 |
| Lancashire | 0 |
| Leicestershire | 0 |
| Lincolnshire | 0 |
| London | 2 |
| Middlesex | 0 |
| Northumberland | 0 |
| Norfolk | 0 |
| Northamptonshire | 0 |
| Nottinghamshire | 0 |
| Oxfordshire | 0 |
| Rutland | 0 |
| Shropshire | 0 |
| Suffolk | 0 |
| Somerset | 0 |
| Surrey | 0 |
| Sussex | 0 |
| Staffordshire | 0 |
| Warwickshire | 0 |
| Westmorland | 0 |
| Wiltshire | 0 |
| Worcestershire | 0 |
| Yorkshire | 0 |
| Anglesey | 0 |
| Brecknockshire | 0 |
| Cardiganshire | 0 |
| Carnarvonshire | 0 |
| Carmarthenshire | 0 |
| Denbighshire | 0 |
| Flintshire | 0 |
| Glamorgan | 0 |
| Merionethshire | 0 |
| Montgomeryshire | 0 |
| Monmouthshire | 0 |
| Pembrokeshire | 0 |
| Radnorshire | 0 |
| Profession | Census Frequency |
|---|---|
| Labourer | 1 |
| Shoe Maker | 1 |
| Name | Census Frequency |
|---|---|
| John O Leary | 45 |
| Mary O Leary | 40 |
| James O Leary | 23 |
| Ellen O Leary | 21 |
| Daniel O Leary | 20 |
| Elizabeth O Leary | 19 |
| Michael O Leary | 18 |
| Margaret O Leary | 16 |
| Catherine O Leary | 15 |
| Patrick O Leary | 15 |
| William O Leary | 14 |
| Jane O Leary | 11 |
| Thomas O Leary | 11 |
| Annie O Leary | 10 |
| Alice O Leary | 9 |
| Edward O Leary | 9 |
| Jeremiah O Leary | 9 |
| Arthur O Leary | 8 |
| Cornelius O Leary | 8 |
| Timothy O Leary | 8 |
| Ann O Leary | 7 |
| Dennis O Leary | 6 |
| George O Leary | 6 |
| Joseph O Leary | 6 |
| Sarah O Leary | 6 |
| Rank | Surname | Match | Census Frequency |
|---|---|---|---|
| 1 | O Brien | 29% | 4,889 |
| 2 | O Neill | 43% | 2,288 |
| 3 | O Connor | 25% | 2,195 |
| 4 | O Neil | 43% | 2,053 |
| 5 | O Donnell | 22% | 1,424 |
| 6 | O Hara | 57% | 1,225 |
| 7 | O Brian | 29% | 1,034 |
| 8 | O Connell | 22% | 829 |
| 9 | O' Brien | 25% | 734 |
| 10 | O Hare | 57% | 666 |
| 11 | O Leary | 100% | 566 |
| 12 | O Neal | 57% | 407 |
| 13 | O Niel | 29% | 386 |
| 14 | O Conner | 25% | 382 |
| 15 | O' Neill | 38% | 368 |
| 16 | O Sullivan | 30% | 300 |
| 17 | O Shea | 43% | 299 |
| 18 | O Malley | 38% | 296 |
| 19 | O Reilly | 50% | 286 |
| 20 | O' Connor | 22% | 277 |
| 21 | O Grady | 57% | 249 |
| 22 | O' Hara | 43% | 249 |
| 23 | O' Neil | 29% | 249 |
| 24 | O Rourke | 38% | 228 |
| 25 | O Bryan | 29% | 223 |
| 26 | O Keefe | 43% | 214 |
| 27 | O' Donnell | 20% | 206 |
| 28 | O Toole | 29% | 180 |
| 29 | O Donald | 38% | 163 |
| 30 | O Keeffe | 38% | 150 |
| 31 | O Donoghue | 20% | 140 |
| 32 | O' Brian | 25% | 130 |
| 33 | O Niell | 29% | 128 |
| 34 | O' Connell | 20% | 128 |
| 35 | O Callaghan | 36% | 123 |
| 36 | O Dell | 43% | 115 |
| 37 | Morris | 14% | 114 |
| 38 | O Boyle | 29% | 114 |
| 39 | O Hanlon | 25% | 111 |
| 40 | Owe | 29% | 105 |
| 41 | O' Leary | 88% | 104 |
| 42 | O Hagan | 29% | 100 |
The surname O Leary is the 11th most popular variant of O Brien.