| Country: | Niger |
| Yes: | 3,275,737 |
| No: | 23,713 |
| Invalid: | 7,425 |
| Electorate: | 3,477,874 |
A constitutional referendum was held in Niger on 24 September 1989. The new constitution would make the country a one-party state with the National Movement for the Society of Development as the sole legal party. The government would have a presidential system, as well as the continued involvement of the Armed Forces, which had ruled the country since the military coup in 1974.
It was approved by 99.3% of voters with a 94.9% turnout.[1] The first elections under the new constitution were held later in the year on 12 December.