On 14 March 2009, Stringer put in a Man-of-the-Match performance for Ireland against Scotland during the 2009 Six Nations Championship. Losing 12–9 at half-time in Murrayfield, Stringer made a break and passed to Jamie Heaslip, who scored a match-turning try that eventually saw Ireland win 15–22. A week later, Stringer came off the bench during Ireland's final 2009 Six Nations game against Wales. In the dying minutes of the game, Stringer passed the ball from a ruck to Ronan O'Gara, who then scored the drop-goal that won Ireland's first Grand Slam since 1948.