In 2008 there was speculation that Ó Sé, at the age of thirty-three, would retire from inter-county football. In the end he decided to line out with Kerry once again and help his team in their pursuit of a third All-Ireland title in-a-row. All did not go to plan as Ó Sé's side lost team captain Paul Galvin to suspension after an incident with referee Paddy Russell in the Munster semi-final against Clare. The subsequent Munster final saw Kerry take an eight-point lead over Cork at half-time. 'The Rebels' fought back and, in a massive downpour, Kerry could only muster three points in the second period of play as Cork secured a remarkable 1–16 to 1–11 victory. Furthermore, Ó Sé picked up a red card after an altercation with Pearse O'Neill. Kerry worked their way through to the All-Ireland semi-final where they faced Cork once again. 'The Kingdom' were much better in this encounter; however, Ó Sé received a straight red card for an incident with Pearse O'Neill once again. At this stage of the game Kerry were cruising and it looked as if Ó Sé would miss the All-Ireland final. Two very late goals by Cork secured a draw. The replay was also an exciting affair; however, Kerry overcame Cork in their third championship meeting that year. An All-Ireland final appearance against Tyrone was the reward for this victory, with Ó Sé lining out at midfield again. An exciting game developed, one that was more competitive than the routs that had taken place at the same stage of the championship over the previous two years. The sides were level seven times before Colm Cooper nudged Kerry 0–8 to 0–7 ahead before the interval. Tyrone simply wore Kerry into the ground in the second half as a priceless goal from Tommy McGuigan and a string of late points inspired Tyrone to their third All-Ireland title of the decade.