Basic demographic statistics include national population numbers disaggregated by age and sex; age dependency and sex ratios; crude birth, death and migration rates; annual population growth rates, including rural and urban growth rates; and key demographic indicators such as fertility, mortality and migrations rates.
| Census Date | Year | Males | Females | Total |
| 1900 | 1765 | 2250 | 4,015 | |
| June | 1902 | 1908 | 2166 | 4,074 |
| 1-Jun | 1906 | 1774 | 2048 | 3,822 |
| 17-Nov | 1911 | 1855 | 2088 | 3,943 |
| 15-Oct | 1916 | 1828 | 2052 | 3,880 |
| 17-Apr | 1921 | 1736 | 2014 | 3,750 |
| 20-Apr | 1926 | 1781 | 2014 | 3,795 |
| 31-Dec | 1931 | 1794 | 2003 | 3,797 |
| 24-Mar | 1936 | 1991 | 2113 | 4,104 |
| 25-Sep | 1945 | 2054 | 2199 | 4,253 |
| 27-Sep | 1951 | 2231 | 2322 | 4,553 |
| 25-Sep | 1956 | 2279 | 2428 | 4,707 |
| 25-Sep | 1961 | 2404 | 2460 | 4,864 |
| 28-Sep | 1966 | 2533 | 2661 | 5,194 |
| 28-Sep | 1971 | 2507 | 2483 | 4,990 |
| 1974 | 2005 | 1987 | 3,992 | |
| 28-Sep | 1976 | 1928 | 1915 | 3,843 |
| 10-Mar | 1979 | 1823 | 1755 | 3,578 |
| 28-Sep | 1981 | 1672 | 1609 | 3,281 |
| 1-Oct | 1984 | 1479 | 1408 | 2,887 |
| 29-Sep | 1986 | 1271 | 1260 | 2,531 |
| 1-Oct | 1989 | 1159 | 1108 | 2,267 |
| 3-Nov | 1991 | 1134 | 1105 | 2,239 |
| 4-Oct | 1994 | 1156 | 1144 | 2,300 |
| October | 1996 | 1055 | 1034 | 2,089 |
| 17-Aug | 1997 | 1053 | 1035 | 2,088 |
| 9-Aug | 1999 | 969 | 944 | 1,913 |
| 11-Dec | 2000 | 944 | 913 | 1,857 |
| 8-Sep | 2001 | 897 | 891 | 1,788 |
| 7-Sep | 2004 | 866 | 895 | 1,761 |
| 8-Sep | 2006 | 802 | 823 | 1,62 |
| 9-Sep | 2011 | 802 | 809 | 1,611 |
| 10-Mar | 2017 | 831 | 888 | 1,719 |
1900: Census conducted unofficially
1902 – 1945: Census conducted under New Zealand Law
1906 – 1945: Census conducted with New Zealand cenuses
1961 – 1966: The Cook Islands Census Regulations 1961 provided the legal basis for these two censuses
1971: Censuses from 1971 onwards were conducted under the 1971 Niue Census Ordinance No. 68
1979: Mini- Census (ad-hoc household survey) conducted especially for developments planning
1984: Mini-census
1996: Based on land area of 259 sq.km
2004: Headcount after Cyclone Heta