The club made the announcement official about 15 minutes after Cook posted a message on his Facebook page indicating that he had been let go.
"Thank you Cincinnati for the memories ... Looking forward to our next opportunity..," he wrote. "Thank you everyone for the support these past seven years, we have made many friends and tons of great memories..."
An undrafted signee out of Michigan State, Cook has spent all six of his NFL seasons with the Bengals. He joined the Bengals in 2007 as a member of the team's practice squad before eventually making the roster. After appearing in only five games in 2008, he played in all 16 games in 2009, 2010, 2011 and 2013. A foot and ankle injury shelved him for all but four games of the 2012 season.
The 30-year-old Michigan native had been regarded by Pro Football Focus as one of the worst centers in the league. He ranked 24th out of 35 starting centers, according to PFF.com.
The announcement on Cook comes four days after the Bengals re-signed guard Mike Pollak to a three-year deal. Noted for his versatility, Pollak is an interior lineman who has experience playing center.
Cook has played in 73 games in his career, making 66 starts.