The list was calculated based on analysis of birth registrations in Ireland during 1890 and published in a report titled 'Special Report on Surnames in Ireland' by Sir Robert E. Matheson in 1909.
| No. | Surname | Est. Total Pop. * |
| 1 | Murphy | 62,600 |
| 2 | Kelly | 55,900 |
| 3 | Sullivan | 43,600 |
| 4 | Walsh | 41,700 |
| 5 | Smith | 33,700 |
| 6 | O'Brien | 33,400 |
| 7 | Byrne | 33,300 |
| 8 | Ryan | 32,000 |
| 9 | Connor | 31,200 |
| 10 | O'Neill | 29,100 |
* Estimated total population with this surname. Full population of Ireland at the time estimated to be about 4,718,000 (Based on census returns and birth and death numbers).
For the full list see :
Top 100 Surnames by birth registrations - 1890Shane
