The former France international, who enjoyed spells with Newcastle, Fulham, Manchester United, Everton, Spurs and Sunderland, took to his Twitter account to deliver the news.
Saha said: "Want to thks all managers, all staffs, all teammates, all opponents, all fans, for all support and love towards me during my football career.
"I'm a proud man but without you all I won't be myself now. Thx for the challenges thx for the help thx for the memories thx for the passion.
"I will stop to be call a professionnel footballer and wish many young talent to enjoy as much as me my football. Love you and thx again."
After starting his career at Metz in 1997, Saha initially played on loan at Newcastle in the second half of the 1998-99 season, making 12 appearances.
Fulham then signed Saha on a permanent basis in the summer of 2000, the Frenchman enjoying a prolific spell with 64 goals in 144 games.
That sparked a £12.8million move to Manchester United in January 2004, with Saha weighing in with 42 goals in 124 appearances.
After four and a half years at Old Trafford, Saha then joined Everton where he scored 35 goals in 115 games, before moving on again to Spurs in January last year, followed by brief spells with Sunderland and Lazio at the end of last season.
Saha also made 20 appearances for France, scoring four goals.