Ramirez, who was with the Detroit Lions last season, signed a one-year contract with the Bears on Wednesday after visiting the team a day earlier.
The 33-year-old Ramirez spent four seasons in Denver with head coach John Fox and offensive line coach Dave Magazu, who are now with the Bears. Ramirez was traded in April 2015 from the Broncos to the Lions in a draft-day deal.
Last season, Ramirez started seven games and played in all 16 for the Lions, bringing his career total to 65 regular-season starts overall since he was drafted in the fourth round by Detroit in 2007.
Ramirez can play both guard and center. He could compete with second-year player Hroniss Grasu for the starting center position this year or provide depth if he does not land a starting spot.