The Wolves reached agreement with the free agent from Portland on Monday and made the announcement Wednesday. Williams gets a one-year, $3.75 million contract to serve as the primary backup to point guard Ricky Rubio.
Williams can play both guard positions, which would allow for the Wolves to play him with Rubio late in games. He will turn 32 in December and is entering his 12th season in the league and the Timberwolves see him as an ideal fit alongside rookie Zach LaVine on the team's second unit.
Williams averaged 9.7 points for the Trail Blazers last season and is a career 38.5 percent shooter from 3-point range.