A news conference is scheduled for Monday afternoon.
Smith, 34, spent 11 seasons in Baltimore and will forever be remembered for stopping Michael Crabtree from making a catch on a fourth-down goal-line stand, which preserved the Ravens' 34-31 Super Bowl XLVII victory over the San Francisco 49ers in February 2013.
A year later, 49ers fans still accused Smith of holding Crabtree in the end zone.
"The only thing I'm holding now is the championship," Smith said in 2014. He has a tattoo of the Ravens' Super Bowl ring on his left forearm.
The Ravens drafted Smith with the No. 27 overall pick of the 2011 draft. Known for his size and ability to shut down top wide receivers, Smith finished with 374 tackles, 74 passes defensed, 14 interceptions and three touchdowns.
Injuries limited him from reaching a Pro Bowl. He missed a total of 49 games in his career.
Smith, who was out of football this season, hinted at retirement toward the end of last season.
"Part of it is, 'Do I even want to put my body through something like this again?'" Smith said last year. "So I do cherish these last games. I'm getting old. I've been through a lot of injuries, and they start to pile up on you."