The Northern Ireland general election, 1921 was held on 24 May 1921. It was the first election to the Parliament of Northern Ireland. Ulster Unionist Party members won a two-thirds majority of votes cast and more than three-quarter of the seats in the assembly. Sinn Féin in particular was shocked at the scale of the Unionist victory, having spent considerable resources on the campaign, and had expected to win between 1/3 and 1/2 of the seats. The election was conducted using the single transferable vote system.