Born in
Cork, O'Sullivan first began playing rugby for local club
Dolphin's under-10 side. He attended
Presentation Brothers College, representing the school in the
Munster Schools Senior Cup, before progressing to
University College Cork and then joining
Cork Constitution in the amateur
All-Ireland League, whom he would go on to captain. Having previously played for
Munster at under-20 level, though O'Sullivan was injured in the game, which prevented him from making his senior competitive debut for the province until their game
Neath-Swansea Ospreys on 27 September 2003. Internationally, O'Sullivan represented
Ireland Schools and
Ireland under-21s. He died by suicide in March 2006. ==References==