Ceann Comhairle Verona Murphy TD formally announced to Dáil Éireann that Catherine Connolly - a sitting TD - was elected President of Ireland on 25 October.
This followed official notification from the Presidential Returning Officer.
As part of a formal procedure specified in the Presidential Elections Act 1993, Captain Elaine Anthony delivered the notification personally to the Ceann Comhairle last week.
Following this, Article 12.6 of the Constitution stipulates that the person “shall be deemed to have vacated his seat in that House”.
The last time a sitting TD was elected President was over 52 years ago, when Erskine Childers was elected President.