The 17-year veteran played last season with the Atlanta Hawks, averaging 3.6 points in 30 games.
Stackhouse spent the past season as a veteran presence off the bench for the Hawks. The Nets will look to him to be a veteran stabilizing force in the locker room more than the impact player he used to be on the court.
Stackhouse, 37, has career averages of 17.4 points, 3.4 assists and 3.3 rebounds. He was the league's second-leading scorer in 2000-01, averaging a career-best 29.8 points, but he hasn't played more than 40 games since the 2009-10 season, when he averaged 8.5 points in 42 games with the Milwaukee Bucks.
The Nets on Wednesday also announced they had re-signed forward Gerald Wallace to a four-year deal. The team had verbally agreed to a contract with Wallace shortly after free agency began on July 1.