|Full name||Gerard O'Brien|
|Date of birth||2 July 1984|
|Place of birth||Dublin, Ireland|
|Height||1.80 m (5 ft 11 in)|
|Playing position||Right back|
|St Patrick's Athletic|
|St Patrick's Athletic|
|2003||St Patrick's Athletic||0||(0)|
|2003||→ Athlone Town (loan)||32||(1)|
|2012–||St Patrick's Athletic||135||(1)|
|2007–2008||Republic of Ireland U23||3||(1)|
|2011||League of Ireland XI||1||(0)|
|* Senior club appearances and goals counted for the domestic league only.
Ger O'Brien was signed by Eric Hannigan before the start of the 2004 season from Athlone Town. He was the first player to represent the Republic of Ireland at any level while playing with Kildare County. He represented the Eircom League International squad in Aberdeen for the quadrangular tournament with England, Scotland and Wales in 2004. Ger O' Brien made 39 appearances for Kildare County in the 2005 season and was also awarded the clubs player of the season award.
Ger left Kildare County for Shamrock Rovers to become one of the country's best full backs. He missed most of the pre-season campaign in his first year with Shamrock Rovers but once the season began he became a first team regular pretty quickly. He revealed himself to be a tough and uncompromising defender and although he suffered an injury setback in early June he made a quick recovery and picked up where he left off. On 11 November 2007 Ger was voted Shamrock Rovers Player of the Year for the 2007 season and on the 13th he also represented his country in an Under 23 international against Slovakia in Dalymount Park.
After Sporting Fingal ceased trading, O'Brien's contract was cancelled. On the 15, February 2011 Bohemians announced the signing of 9 players including O'Brien. He made his league debut for his new club against Bray Wanderers on 4 March at the Carlisle Grounds.
St Patrick's Athletic
O'Brien signed for the club he supported as a boy, St Patrick's Athletic for the 2012 season. He is the club's vice captain and he skippered the side against Cliftonville in the Setanta Cup due to the absence of captain Conor Kenna. O'Brien started the season off well and after eight league games the Saints defence earned five clean sheets and only conceded three goals. In the 2013–14 UEFA Europa League first qualifying round, O'Brien scored his first goal for the Saints on his 70th appearance when he scored the equaliser in the first leg against VMFD Žalgiris to make it 2–2 in the LFF Stadium in Vilnius, Lithuania.
O'Brien represented the Republic of Ireland U23s in the 2007–09 International Challenge Trophy, playing in all three games. He won his first cap against Slovakia on 13 November 2007 and then earned a second cap in May 2008 against Northern Ireland. He scored on his third appearance against Belgium. Ireland went on to lose the match 2–1.
- Shamrock Rovers
- St Patrick's Athletic
- League of Ireland (1): 2013
- President's Cup (1): 2014
- Leinster Senior Cup (1): 2014
- FAI Cup (1): 2014
- League of Ireland Cup (2): 2015, 2016
- Maynooth University (As manager)
- Kildare County Player of the Year (1): 2005
- Shamrock Rovers Player of the Year (1): 2007
- PFAI Team of the Year (2): 2012, 2013
- St Patrick's Athletic Goal of the Season (1):
- "Debut for Ger". 19 May 2004. Archived from the original on 28 September 2007. Retrieved 22 February 2009.
- "Ireland U23 v Slovakia – Support the eircom league players". 12 November 2007. Archived from the original on 18 November 2007. Retrieved 22 February 2009.
- "City sign O'Brien". 16 February 2009. Archived from the original on 27 July 2009. Retrieved 22 February 2009.
- Bray 1 Bohemians 3 Archived 7 March 2011 at the Wayback Machine.
- "Last gasp goal by Stephen Rice wins it for Republic of Ireland U23s". 13 May 2008. Retrieved 22 February 2009.
- "Belgium stun Republic of Ireland U23s with stoppage time winner". 21 October 2008. Retrieved 22 February 2009.