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DCOS Operations

DCOS Operations

Major General Kieran Brennan is the Deputy Chief of Staff (Ops) effective from 16 June 2015. Major General Brennan was born in 1957 and joined the Defence Forces as a cadet in 1975.

Military Service

On commissioning in 1977, Major General Brennan was assigned to the Infantry Corps and began his career in 12 Infantry Battalion in Limerick. Throughout his career, Major General Brennan has served in key staff and command appointments at Battalion, Brigade and Defence Force Headquarter level.

Among these key appointments have been Instructor, Cadet School, the Military College, Chief Instructor United Nations Training School Ireland, Officer Commanding 3 Infantry Battalion, Stephens Barracks, Kilkenny and Director of Human Resource Management for the Defence Forces. His most recent appointment was General Officer Commanding the 1 Brigade.

Overseas Service

Major General Brennan has extensive overseas experience. He completed two tours of duty with United Nations Interim Force in Lebanon (UNIFIL) in 1982 and 1997. He served as Company Commander with the 28 Irish Infantry Group KFOR as part of a Multinational Battle Group in Kosovo in 2004. In 2008 Major General Brennan commanded the 98 Infantry Battalion with the EUFOR Mission in Chad, and in 2010 he served as Deputy Military Advisor to the Permanent Mission of Ireland to the Organisation for Security and Cooperation in Europe in Vienna.


Major General Brennan is a graduate of the Irish Defence Forces Military College where he completed both Junior and Senior Command and Staff Courses. He studied Economics, Finance and Accountancy at National University of Ireland, Galway, graduating with a Bachelor of Commerce Degree.


Major General Brennan is a native of Jenkinstown, Co. Kilkenny and has a keen interest in sport. He won two All-Ireland senior hurling medals in 1982 and 1983 and received a GAA All Star Award in 1984.

Major General Brennan is married to Maria and they have three children; Karen is a National School teacher while Kieran and Shane are serving Officers in the Defence Forces.