He was traded by the Dolphins to the Bears for wide receiver Marty Booker and a 3rd round pick in the 2005 NFL draft after holding out during the month of August before the 2004 NFL season. Ogunleye quickly signed a record-breaking 6-year contract with the Bears. During the next six seasons Ogunleye became a mainstay on the Bears top-ranked defense. During the 2005 NFL season, Ogunleye spearheaded the Bear's defensive line by recording ten sacks. Ogunleye was named team captain and helped the Bears reach Super Bowl XLI in Miami during the 2006 season.