Gerard O'Brien (born 2 July 1984) is an Irish former professional footballer who played in the League of Ireland as a defender.

His former clubs also include Athlone Town, Kildare County, Shamrock Rovers, Derry City, Sporting Fingal, Bohemians.

He represented the Eircom League International squad in Aberdeen for the quadrangular tournament with England, Scotland and Wales in 2004.

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.

O'Brien started the season off well and after eight league games the Saints defence earned five clean sheets and only conceded three goals.

[10][11] Since taking over the role as Director of Coaching, St Patrick's Athletic have had unprecedented success at academy level.