The deal was announced by Boca during Argentina’s Copa America quarter-final penalty shootout victory over Colombia, in which Tevez scored the winning spot kick.
The 31-year-old began his career at Boca as a teenager before moving to Brazilian side Corinthians in 2005 and the Buenos Aires club had repeatedly been linked with a move for the striker in recent months.
Newspaper reports had claimed that Paris St-Germain, Liverpool and Atletico Madrid had also been interested in acquiring Tevez’s services, but Boca have won the race for his signature.
“It is a day of joy and great satisfaction,” Boca president Daniel Angelici told the club’s official Facebook page.
“The return of Carlos Tevez in an extraordinary moment of his career is fantastic news for all partners and supporters of Boca and Argentine football.
“The presence of Carlos will give another leap in quality to the great squad we have.”
Tevez scored 20 league goals last season to help Juve clinch their fourth straight Serie A title and notched seven more in 13 games as the Bianconeri reached the Champions League final where they lost 3-1 to Barcelona.
He joined the Turin giants in a £10m deal in 2013 after a seven-year spell in England with West Ham, Manchester United and Manchester City which saw him win three Premier League titles and one Champions League crown.