The club announced the deal on its official website Wednesday. The deal is reportedly worth $2.5 million plus incentives and bonuses.
The 34-year-old Jones hit .215 with five home runs and 17 RBIs in 57 games for the Yankees this season.
He has a .251 career batting average with 122 home runs. He hit a career-high 27 home runs in 2012 for the Pittsburgh Pirates.
The acquisition gives the Giants a pair of left-handed hitting foreign outfielder/first basemen following the club's announcement that it had retained Leslie Anderson of Cuba for his third season at an estimated cost of $450,000.