An election to Belfast Corporation took place in January 1920 as part of that year's Irish local elections. The had seen elections for local government in Ireland change to a more proportional system. As a result, Unionist dominance of the Belfast council was somewhat undermined, and the party lost 15 seats. In contrast Labour, Sinn Féin, and Nationalist representation grew, resulting in a more politically and socially representative council. After the election Sir William Coates, 1st Baronet was elected by the new council as Lord Mayor of Belfast.