Fiora, who was chosen by Richmond with pick No.3 in the 1999 AFL Draft, played 78 games with the Tigers before being traded to St Kilda in 2004.
He has kicked 58 goals in his AFL career.
The Saints also announced that Xavier Clarke and James Gwilt had signed new deals that will see them remain with the club for at least one more year.
The 25-year-old Clarke played eight games in an injury interrupted 2008 season while Gwilt, 22, played 13 matches, including St Kilda's three finals.
St Kilda's general manager of fFootball and list management, Matthew Drain, said, "We are delighted that Xavier and James have put pen to paper and committed to at least another year at the Saints. They are both young, valued members of the squad and we believe they have a lot to offer going forward."
