Former Portsmouth striker Benjani has secured a return to Fratton Park after seeing out his contract with Blackburn Rovers.
The Zimbabwean was offered a chance to remain at Ewood Park, but has instead decided to join the Championship club after seeing limited opportunities under manager Steve Kean.
Benjani scored 19 goals in 77 appearances for Portsmouth in his two seasons at the club, which earned him a move to the City of Manchester Stadium in 2008.
The 33-year-old's original transfer to the club from Auxerre in 2006 was among those covered by the 2007 Stevens inquiry.
