A key part of the Giants' Super Bowl championship team a year ago, the 30-year-old Boley appeared in all 16 games last year with 11 starts but was hampered by hamstring, hip and shoulder injuries at various times. He finished on third the team with 84 tackles and had three interceptions, one in each of the first three games.
He had one year and about $4 million left on the five-year, $25 deal he signed when joining the Giants as a free agent in 2009 after four seasons with the Atlanta Falcons.
In his four seasons with New York, he played in 57 games with 50 starts, most of them at weakside linebacker. His had 315 tackles (237 solo), 3 1/2 sacks, three interceptions, 15 passes defensed, two forced fumbles and five fumble recoveries, including a 65-yard return for a touchdown in 2011 and the 70-yarder in 2012.
In the Super Bowl win over the New England Patriots in Indianapolis, he had a team-high 10 tackles.
"Michael Boley was brought here as a fast, athletic, versatile linebacker," coach Tom Coughlin said. "We recognized his special skills were in coverage. He's a smart player who made some big plays for us. He was an integral part of our Super Bowl XLVI championship team. Michael played outstanding football down the stretch for us that season."
The release of Boley opens the door for third-year linebacker Jacquian Williams to play a bigger role.
Boley was a leader on the defense, but changes happen after a unit finishes 31st and plays poorly late in the season, which the defense did in one-sided losses to Atlanta and the eventual Super Bowl champion Baltimore Ravens.
"Michael came in and learned our defense quickly and he added speed, coupled with big play ability, to our defensive unit," general manager Jerry Reese said. "He also played an important role in helping us win Super Bowl XLVI. I wish him well as he moves forward in his career."
Boley has played in 121 regular-season games with 102 starts. He has started all five postseason games in which he has played. His career regular-season totals include 680 tackles (497 solo), 9.5 sacks, eight forced fumbles, eight fumble recoveries, 40 passes defensed and eight interceptions. In the postseason, Boley has had 28 tackles (22 solo) and two sacks.