The Northern Ireland Assembly was a legislative assembly set up by the Government of the United Kingdom on 3 May 1973 to restore devolved government to Northern Ireland with the power-sharing Northern Ireland Executive made up of unionists and nationalists. It was abolished by the Northern Ireland Act 1974.

Elections were held on 28 June 1973. The Northern Ireland Constitution Act 1973, which received the Royal Assent on 18 July 1973, abolished the suspended Parliament of Northern Ireland and the post of Governor and made provision for a devolved administration consisting of an Executive chosen by the Assembly.

108 members were elected by Single Transferable Vote from Northern Ireland's 18 Westminster constituencies, with 5 to 8 seats for each depending on its population.

The Assembly met for the first time on 31 July 1973. Following the Sunningdale Agreement, a power-sharing Executive was established from 1 January 1974. After opposition from within the Ulster Unionist Party (UUP) and the Ulster Workers' Council strike over the proposal of an all Ireland council, the Executive and Assembly collapsed on 28 May 1974 when Brian Faulkner resigned as Chief Executive.