The agreement calls for a five-year contract, Tulloch's agent, Drew Rosenhaus confirmed for The Associated Press on Tuesday.
Re-signing Tulloch was one of the Lions' goals after he helped them earn a spot in the playoffs for the first time since the 1999 season. He shopped his services on the market as an unrestricted free agent, but got the long-term deal he was looking for in Detroit.
"I want to thank all of the Detroit Lion fans for sticking with me through this process," read a message posted on Tulloch's Twitter account. "This is a special team & I'm glad to be apart of it."
Tulloch made a team-high 111 tackles with the Lions after signing a one-year deal last summer. Tulloch led Tennessee in tackles the previous two years after being drafted by the Titans in 2006, when their defensive coordinator was current Detroit coach Jim Schwartz.
The Lions vowed they would find ways to keep their best players after going years trying to add talent from other teams, and pulled it off with one exception. Cornerback Eric Wright, who signed last week with Tampa Bay, is the only player Detroit wanted back that won't return.
The Lions extended All-Pro receiver Calvin Johnson's contract for eight more seasons, retained defensive end Cliff Avril for at least another season with a franchise tag and re-signed offensive tackle Jeff Backus and backup Shaun Hill to two-year contracts. Detroit also has bolstered its depth by re-signing safety Erik Coleman and defensive tackle Andre Fluellen to one-year deals.