The inside linebacker ranks first in franchise history with 1,118 tackles.
"I spent nine great years in Green Bay," Hawk said in a team statement. "I had awesome teammates and coaches and a great medical staff and equipment staff. Many of them have become my closest friends. We won a ton of games, as well as a Super Bowl, and I loved everything about playing for one of the greatest franchises in all of sports.
"The fans in Green Bay are incredible. Between playing at Lambeau Field as well as seeing them on the road, they always supported us. I am looking forward to my next opportunity in the NFL, but I'll always cherish my years as a Green Bay Packer."
Hawk is currently recovering from surgery to remove bone spurs in his ankle.
The 31-year-old has not played well in recent seasons. His struggles were one of a plethora of reasons Green Bay moved Clay Matthews inside at times in 2014.
The move thrusts even more questions on the Packers' inside linebacker position, which was an area of need even before this transaction.
Hawk's release comes less than a week after general manager Ted Thompson clipped fellow inside linebacker Brad Jones.
The Packers will focus on the inside backer position in free agency and through the NFL draft. The release of two inside linebackers indicates that Matthews should play inside even more next year, despite coach Mike McCarthy's proclamation that he's best on the outside. Green Bay clearly wasn't going to enter 2015 with the same core that faltered last season.