The Irish population taken from various census results, and estimates.
| Eire | |
| Year | Population |
| 2011 | 4,580,000 |
| 2006 | 4,240,000 |
| 2002 | 3,920,000 |
| 1996 | 3,630,000 |
| 1991 | 3,530,000 |
| 1986 | 3,540,000 |
| 1981 | 3,440,000 |
| 1979 | 3,370,000 |
| 1971 | 2,980,000 |
| 1966 | 2,880,000 |
| 1961 | 2,820,000 |
| 1956 | 2,900,000 |
| 1951 | 2,960,000 |