| Honorific Prefix: | Major General |
| Maureen O'Brien | |
| Birth Place: | Galway, Ireland |
| Allegiance: |  Ireland |
| Branch: | Army Infantry Corps |
| Serviceyears: | 1981–present |
| Rank: | Major General (OF-7) |
| Commands: | Deputy Force Commander UNDOF Director J6 Officer Commanding 27 Infantry Battalion Deputy Commander 100 Inf Bn MINURCAT |
Major General Maureen O'Brien is an Irish Army general and current Deputy Military Advisor in the United Nations Office of Military Affairs, Department of Peace Operations.[1] O'Brien had previously been Deputy Force Commander of the United Nations Disengagement Observer Force (UNDOF) in the Golan Heights from September 2019 to March 2021 (and Acting Force Commander from October 2019 to July 2020).[1]
O'Brien has completed 8 overseas missions, including serving in Lebanon, Western Sahara, East Timor, Sarajevo (OSCE) and Chad, and is the first female promoted to the rank of general in the history of the Irish Defence Forces.
O'Brien is a native of Galway city, and graduated from University College Galway with a Bachelor of Science and Higher Diploma in Education.
She holds a first class master's degree in Leadership, Management and Defence Studies from Maynooth University and has completed a postgraduate diploma in IT from University College Cork.[2]
After spending time as a teacher, O'Brien joined the Cadet School in 1981 - one year after the Army allowed women to apply. On commissioning in 1983 she was posted as an Infantry Officer, to the 4th Infantry Battalion, Cork, before returning to the Cadet School some years later as an instructor.
O'Brien has achieved a number of "firsts" for women in the Irish Defence Forces,[3] becoming the first female Army Line Officer to be promoted to lieutenant colonel in 2011 as Battalion Commander of the 27 Infantry Battalion in Aiken Barracks, and as Colonel assuming the role as Director of the CIS Corps in 2016, responsible for all communications and information technology across the Army, Naval Service and Air Corps.
Her career has included extensive overseas experience, with her first two deployments being to the United Nations Interim Force in Lebanon, serving as a Captain in MINURSO in the Western Sahara and UNTAET in East Timor. She assumed the role as Second-in-command (2IC) of a 420-strong infantry battalion with MINURCAT in Chad and was deployed as Chief of Operations Planning in a multinational sector headquarters in Lebanon (UNIFIL). O'Brien has held appointment in the Operations Branch of Defence Forces Headquarters where she was the senior staff officer responsible for EU and NATO/PfP engagement.[4]
At the time of her promotion in 2019 to brigadier general, O'Brien was described as "one of the most accomplished officers operationally in the Defence Forces".[5] As Deputy Force Commander, O'Brien was responsible for ensuring that directives were met within UNDOF for the force commander, and for liaising with the Israel Defense Forces (IDF) and Syria.[6]
In May 2021, O'Brien was appointed to the second highest rank in the Irish Defence Forces (major general) as one of two advisors on United Nations peacekeeping operations to the UN Secretary General.[7]