The fusion of the Belgian municipalities (French: fusion des communes, Dutch: fusie van Belgische gemeenten) was a Belgian political process that rationalized and reduced the number of municipalities in Belgium between 1975 and 1983. In 1961, there were 2,663 such municipalities; by 1983, these had been re-arranged and combined into 589 municipalities.
After several decades without any change, fifteen Flemish municipalities will be merged into seven effective 1 January 2019, reducing the number of Flemish municipalities from 308 to 300, and the Belgian total from 589 to 581.