After being called up by newly appointed Manager Giovanni Trapattoni, He made his debut in a friendly against Nigeria at Craven Cottage on 29 May 2009, and played his first competitive match a week later, a 1–1 draw away to Bulgaria in a qualifying game for the 2010 FIFA World Cup. St Ledger scored his first goal for Ireland in a 2–2 with Italy at Croke Park, Dublin, in a FIFA World Cup qualifier in October 2009. The goal gave Ireland a late lead against the World Champions and was almost St Ledger's "Ray Houghton" moment, guaranteeing him iconic status in only his sixth appearance, only for Alberto Gilardino to score an even later equaliser for the Italians.