Leicester City player said that it is an honour to play for Giovanni Trapattoni and reckons the Irish team may cause a surprise
The 27-year-old was named in Giovanni Trapattoni's 23-man squad for the finals and is hoping to add to the 24 caps he has earned for his country so far this summer.
"We're obviously going to be underdogs, but we're going out there not just to make up the numbers, but try to progress and go as far as we can in the tournament," St Ledger told BBC Radio Leicester.
St Ledger referred to Ireland's upset of Italy at the 1994 World Cup and said the current squad could well spring a surprise in their difficult Group C, which features Croatia, Italy and Spain.
"I think everyone expects us not to win a game in the group (but) history shows in tournaments we often spring an upset. If you compare the Euros to the World Cup, bar the likes of Argentina and Brazil, you'd have to say the Euros is stronger than the World Cup," he said.
Despite not being a regular for his club this season the Leicester City man has remained a favourite of Trapattoni, who handed him his debut back in 2009.
"To say I've worked under a manager like that is a real honour. He's a very good motivator. I think it's his enthusiasm that sets him apart from most managers. That love and passion for the game comes through to the boys."
He also paid tribute to Ireland's supporters which are expected to travel in their thousands to support their country at their first major tournament appearance in a decade.
"We've got so many fans travelling over and the support we had during the campaign was second to none. I believe we've got the best fans in the world and I'm sure the drinks will be flowing over in Poland and everyone will be having a great time," said St Ledger who added that his father and younger brother will making the trip to Poland to cheer him on.
He added that the prospect of taking on the country of his birth (England) or bitter foes France in the knockout phase would be 'unbelievable.'
"We're going there to try to look to qualify and I think if we did get through and played either England or France with our history it would obviously be unbelievable."