|Governor of Northern Ireland|
|Precursor||Lord Lieutenant of Ireland|
|Formation||9 December 1922|
|First holder||The 3rd Duke of Abercorn|
|Final holder||The Lord Grey of Naunton|
|Abolished||18 July 1973|
|Succession||Secretary of State for Northern Ireland|
do and execute in due manner as respects Northern Ireland all things which by virtue of the  Act and our said Letters Patent of 27 April 1921 or otherwise belonged to the office of Lord Lieutenant at the time of the passing of the Irish Free State Constitution Act 1922.
The governor had possession of the Great Seal of Northern Ireland.
The governor was the successor to the Lord Lieutenant of Ireland in Northern Ireland, itself established on 3 May 1921.[a] The office of the governor was abolished on 18 July 1973 under Section 32 of the Northern Ireland Constitution Act 1973. The secretary of state for Northern Ireland, a cabinet office that had been created in 1972, took over the functions of the governor on 20 December 1973 under Letters Patent.
The official residence of the governor of Northern Ireland was Hillsborough Castle in County Down. Following refurbishment of the Castle, the Duke of Abercorn took up residence in 1925. It remained the official residence until the abolition of the office of governor in 1973; henceforth it has been the official residence of the secretary of state for Northern Ireland.
|Term of office||Monarch||Prime Minister|
|Took office||Left office||Time in office|
|1||Duke of Abercorn
|1922||1945||22 years, 268 days||George V
|1945||1952||7 years, 85 days||George VI
|1952||1964||12 years, 0 days||Elizabeth II||Brookeborough|
|4||Lord Erskine of Rerrick
|1964||1968||3 years, 362 days||O'Neill|
|5||Lord Grey of Naunton
|1968||1973||4 years, 211 days||O'Neill|
The 1922 "Instructions" sent alongside the letters patent establishing the office required the governor of Northern Ireland to get the monarch's permission to leave Northern Ireland, and empowered the governor in such cases to issue letters patent under the Great Seal of Northern Ireland appointing a "Deputy or Deputies, Justice or Justices" during his absence. This emulated the practice of appointing Lords Justices of Ireland when the lord lieutenant was absent from Ireland. Each new governor upon taking office would select a slate of eligible deputies from among the Privy Council of Northern Ireland, and at each of his subsequent absences a subset of these would be sworn in for its duration. Many were Lord Chief Justice or Lord Justice of Appeal: Denis Henry, William Moore, James Andrews, Anthony Babington, John MacDermott, Baron MacDermott, Samuel Clarke Porter. Others were Senators and/or county lieutenants: Robert Sharman-Crawford, Robert David Perceval-Maxwell, Henry Armstrong, Sir Thomas Dixon, 2nd Baronet, Maurice McCausland, Francis Needham, 4th Earl of Kilmorey.