And he insisted he would not be coming to Australia for a holiday, proclaiming his desire to score goals, win trophies and help raise the profile and standard of the league.
"I'm coming to Sydney to score and to win and I'm hoping that Australian football, with my help, can grow. I've got the desire and determination to help the sport grow that's a big drive for me.
"I want to play in front of full stadiums.
"It's a great honour there is so much excitement about me coming to Australia.
"I will give everything and put everything into it I can.
As well as the likes of Liverpool, Southampton, Celtic and Sporting Braga, Sydney also beat off interest from the Middle East, US and South America.
"We touched all the continents," Del Piero said. "This choice is far away in terms of kilometres but it's very close in terms of philosophy.
"I can't wait to go and discover a country that everyone describes to me as fantastic."
Del Piero's 19-year career with Juventus ended last season when he was not offered a new deal after they had won their first league title since 2003.
It is hoped his arrival will greatly boost interest and attendances in the A-League, with some pundits likening his arrival to that of Pele and David Beckham's stints in America's MLS.
Remarkably - and in stark contrast to many of the journeymen that have graced the A-League - Sydney will become just Del Piero's third senior club.
He began his professional career at Padova, where he played only 14 games before being signed by Juventus in 1993.
He remained with the Turin-based club until 2012 having scored 208 goals in 513 appearances and was a member of the Italy side that beat France on penalties in the 2006 World Cup final.
While Del Piero's presence will add obvious benefits off the park, Socceroos midfielder Mark Bresciano believes his long-time rival will also have plenty to offer on the pitch.
"I think as a player, he can still perform, even at 37," Bresciano, who spent more than a decade in the Serie A, told Fox Sports.
"When he came off the bench last season for Juve, he changed games and scored goals. He's also a good man - a good pro, who will take it seriously."
"We're honoured to have Alessandro sign for Sydney FC," club chief executive Tony Pignata said, sitting next to Del Piero at a press conference in Turin. "It's a momentous occasion."
Pignata added that Del Piero will have his familiar No.10.
Sydney chairman Scott Barlow called the signing a major coup for the club and a historic day for Australian football.
"This is for all Australian football fans," Barlow added in a statement.
"Alessandro Del Piero is a global icon of the game and we are honoured he has chosen Sydney FC, ahead of many other options, as the club where he will begin the next chapter of his illustrious football career."
- AAP
