The Titans announced the deal Wednesday. Terms were not disclosed.
General manager Ruston Webster said in a statement they are excited to reach an agreement with Casey. The general manager says Casey earned the deal with his play on the field and his work ethic and that the Titans appreciate his professionalism throughout the process.
A third-round draft pick in 2011, Casey is coming off a career year with 10.5 sacks, 90 tackles and 10 quarterback pressures. His sacks were the second-highest total in franchise history for a defensive tackle behind only Ray Childress' 13 sacks in 1992.
Casey has not missed a day this year, saying he wanted to focus on football.