The move comes a day after a league source confirmed that the Bears were releasing two-time Pro Bowl cornerback Kyle Fuller in a move that frees up $14 million in salary-cap space.
Trufant joins a Bears depth chart that is led by second-year cornerback Jaylon Johnson, the starter on the side opposite Fuller's old post.
Trufant, 30, was the Lions' Week 1 starter but was limited to six games because of hamstring issues and finished with an interception and four passes defended. He has missed 17 games due to injuries the past two seasons.
This is the second straight year he was released. In 2020, he was released by the Atlanta Falcons after seven seasons with the franchise.
A first-round pick of Atlanta in 2013, Trufant made the Pro Bowl in 2015 and has started all 103 games he's played during his career, making 14 interceptions with 83 passes defended, 3 forced fumbles and 7 fumble recoveries.
ESPN's Michael Rothstein contributed to this report.