# Chief of Staff of the Defence Forces (Ireland)

The Chief of Staff of the Defence Forces (COS) (Irish: Ceann Foirne na bhFórsaí Cosanta) is charged with the executive management of the Irish Defence Forces, and is the most senior military officer of the Army, Naval Service and Air Corps branches. The Chief of Staff is appointed by the President of Ireland, who is the Supreme Commander of the Defence Forces, on the recommendation of the Minister for Defence subject to the approval of the Government of Ireland. The office of the Chief of Staff consists of his personal staff, a strategic planning office, a public relations section and the military judge.
The Defence Forces Chief of Staff sits on the government's National Security Committee (NSC).
The Chief of Staff delegates remaining executive duties to two deputy chiefs of staff (who hold the rank of major general or equivalent) and one assistant chief of staff (brigadier general or equivalent);
* The Deputy Chief of Staff Operations (D COS Ops) is tasked with operational matters.
* The Deputy Chief of Staff Support (D COS Sp) is tasked with military support matters.
* The Assistant Chief of Staff Support (ACOS Sp) is also tasked with military support matters.
The current Chief of Staff of the Defence Forces is Lieutenant General Sean Clancy.

## Current General Staff of the Defence Forces

| Position | Abbreviation | Incumbent | Branch |
| Chief of Staff | COS | Brigadier General Rossa Mulcahy | Army |
| Deputy Chief of Staff Operations | D COS Ops | Major General Anthony McKenna | Army |
| Deputy Chief of Staff Support | D COS Sp | Major General Adrian Ó Murchú | Army |
| Assistant Chief of Staff | ACOS | | |

### Overseas

| Deputy Military Advisor to UN Office of Military Affairs | Major General Maureen O'Brien | Army |
| Irish Military Representative to the EUMC | Brigadier General Philip Brennan | Army |

## Brigade Commanders

The country is divided into two areas for administrative and operational reasons, and in each area there is an Irish Army infantry brigade. The two brigade group structure envisages distinct operational areas of responsibility for each of the brigades and is supported in their responsibilities by the Naval Service and Air Corps. Each of the Brigade formations and the Air Corps are commanded by a Brigadier General, while the Naval Service is commanded by a Commodore;
| Position | Branch | Abbreviation | Incumbent |
| General Officer Commanding | 1st Brigade (Army) | GOC 1 Brigade | Brigadier General Brian Cleary |
| General Officer Commanding | 2nd Brigade (Army) | GOC 2 Brigade | Brigadier General Tony Cudmore |
| General Officer Commanding | Defence Forces Training Centre (Army) | GOC DFTC | Brigadier General Brendan McGuinness |
| General Officer Commanding | Air Corps | GOC Air Corps | Brigadier General Rory O'Connor |
| Flag Officer Commanding | Naval Service | FOCNS | Commodore Michael Malone |

## List of Irish Chiefs of Staff

| No. | Chief of Staff | Took office | Left office | Time in office | Defence branch |
| 1 | O'Duffy, EoinGeneral Eoin O'Duffy (1890–1944) | February 1922 | July 1922 | 5 months | Army |
| 2 | Mulcahy, RichardGeneral Richard Mulcahy (1886–1971) | July 1922 | August 1922 | 1 month | Army |
| 3 | Mac Mahon, SeánGeneral Seán Mac Mahon (1893–1955) | August 1922 | March 1924 | 1 year, 7 months | Army |
| 4 | MacMahon, PeadarGeneral Peadar MacMahon | March 1924 | March 1927 | 3 years | Army |
| 5 | Hogan, DanielGeneral Daniel Hogan (1895–?) | March 1927 | February 1929 | 1 year, 11 months | Army |
| 6 | Mac Eoin, SeánGeneral Seán Mac Eoin (1893–1973) | February 1929 | October 1929 | 8 months | Army |
| 7 | Sweeney, JosephLieutenant General Joseph Sweeney (1897–1980) | October 1929 | October 1931 | 2 years | Army |
| 8 | Brennan, MichaelLieutenant General Michael Brennan (1896–1986) | October 1931 | January 1940 | 8 years, 3 months | Army |
| 9 | McKenna, DanielLieutenant General Daniel McKenna | January 1940 | January 1949 | 9 years | Army |
| 10 | Archer, LiamLieutenant General Liam Archer | January 1949 | January 1952 | 3 years | Army |
| 11 | Egan, W.Lieutenant General W. A. Egan | January 1952 | December 1954 | 2 years, 11 months | Army |
| 12 | Mulcahy, PatrickLieutenant General Patrick Mulcahy | January 1955 | December 1959 | 4 years, 11 months | Army |
| 13 | McKeown, JohnLieutenant General John McKeown (1910–1998) | January 1960 | December 1960 | 11 months | Army |
| 14 | Powell, SeanLieutenant General Sean Collins Powell (1905–1991) | January 1961 | March 1962 | 1 year, 2 months | Army |
| (13) | McKeown, JohnLieutenant General John McKeown (1910–1998) | April 1962 | March 1971 | 8 years, 11 months | Army |
| 15 | Delaney, PatrickMajor General Patrick Delaney | April 1971 | July 1971 | 3 months | Army |
| 15 | O'Carroll, ThomasLieutenant General Thomas O'Carroll | April 1971 | July 1976 | 5 years, 3 months | Army |
| 16 | O'Sullivan, CarlLieutenant General Carl O'Sullivan | August 1976 | June 1981 | 4 years, 11 months | Army |
| 17 | Hogan, LouisLieutenant General Louis Hogan DSM (1921–2001) | June 1981 | April 1984 | 2 years, 10 months | Army |
| 18 | O'Sullivan, GeraldLieutenant General Gerald O'Sullivan | April 1984 | February 1986 | 1 year, 10 months | Army |
| 19 | O'Neill, TadghLieutenant General Tadgh O'Neill | February 1986 | October 1989 | 3 years, 8 months | Army |
| 20 | Parker, JamesLieutenant General James Parker (1929–2020) | October 1989 | April 1992 | 2 years, 6 months | Army |
| 21 | Bergin, NoelLieutenant General Noel Bergin | April 1992 | December 1994 | 2 years, 8 months | Army |
| 22 | McMahon, GeraldLieutenant General Gerald McMahon | February 1995 | August 1998 | 3 years, 6 months | Army |
| 23 | Stapleton, DavidLieutenant General David Stapleton DSM | August 1998 | 24 September 2000 | 2 years, 1 month | Army |
| 24 | Mangan, ColmLieutenant General Colm Mangan | 25 September 2000 | 20 February 2004 | 3 years, 4 months | Army |
| 25 | Sreenan, JamesLieutenant General James Sreenan | 21 February 2004 | 28 June 2007 | 3 years, 4 months | Army |
| 26 | Earley, DermotLieutenant General Dermot Earley DSM (1948–2010) | 28 June 2007 | 9 June 2010 | 2 years, 11 months | Army |
| 27 | McCann, SeanLieutenant General Sean McCann | 9 June 2010 | 12 August 2013 | 3 years, 2 months | Army |
| 28 | O'Boyle, ConorLieutenant General Conor O'Boyle | 12 August 2013 | 29 September 2015 | 2 years, 1 month | Army |
| 29 | Mellett, MarkVice Admiral Mark Mellett DSM (born 1958) | 29 September 2015 | 29 September 2021 | 6 years | Naval Service |
| 30 | Clancy, SeánLieutenant General Seán Clancy | 29 September 2021 | 4 March 2025 | 3 years, 5 months | Air Corps |
| 30 | Mulcahy, RossaBrigadier General Rossa Mulcahy | 4 March 2025 | Incumbent | 0 months | Army |