|Irish name||Killian Mac Oscair|
25 April 1987|
Collinstown, County Westmeath, Ireland
|Lough Lene Gaels|
Born in Collinstown, County Westmeath, Cloonan first excelled at hurling in his youth. He arrived on the inter-county scene when he first linked up with the Westmeath minor team, before later joining the under-21 side. He made his senior debut in the 2004 National Hurling League. Cosgrove went on to play a key role for Westmeath, and won one Christy Ring Cup medal in 2005.
At club level Cosgrove plays with Lough Lene Gaels.
Cosgrove was forced to retire due to injury after the 2009 Christy Ring Cup.
His father, Michael, also played hurling with Westmeath and later served as manager of the team.
- "Killian Cosgrove". Hurling Stats website. Retrieved 23 January 2014.
- "Hurling reunion brings back old memories for Cosgrave". Hogan Stand website. 1 February 2006. Retrieved 23 January 2014.