A constitutional referendum was held in the Republic of the Congo (Léopoldville) between 25 June and 10 July 1964.

Following the Congo Crisis, negotiations between politicians resulted in the drafting of a new constitution.

It also made the country more federalist, and increased the number of provinces from six to 21.

[1] The country was renamed the "Democratic Republic of Congo" (having been officially the "Republic of Congo" since independence in 1960, a name shared by its neighbour) When the constitution came into effect, the parliament elected in 1960 was automatically dissolved, and the President, Joseph Kasa-Vubu, appointed a transitional government, whose role was to organise elections within nine months.

In June 1964 Kasavubu appointed Moise Tshombe, who had led the Katanga breakaway, as the interim Prime Minister.