After offering longtime middle linebacker Brian Urlacher a one-year, $2 million contract that he refused, the Bears got Williams for a base salary of $900,000, the Chicago Tribune reported. He can earn a maximum of $1.75 million if he reaches all his incentives.
"We are happy to welcome D.J. to the Bears and are excited to start working with him," Bears general manager Phil Emery said in a statement. "This is a great opportunity for D.J. to restart his career after coming off suspension for part of the 2012 season. We see a player that has very good athletic upside who can contribute immediately at 'Mike' (middle) linebacker. He is also a versatile player who has played both outside linebacker positions, giving us flexibility in the draft."
Williams spent nine years in Denver where he started 115 regular-season games and registered a career-best 141 tackles in 2007. The 30-year-old veteran has played both middle and outside linebacker.
He appeared in just seven games last season with one start after being suspended nine games by the NFL for two separate incidents. He was suspended the first six games of the 2012 season for violating the league's banned-substances policy after the league said he supplied a "non-human" urine sample during a drug test.
NFL commissioner Roger Goodell tacked on an additional three-game suspension after Williams was found in violation of the league's substance abuse policy when a jury convicted him of driving while impaired in a case that dated to November 2010. That incident was the second time Williams had been arrested under the suspicion of driving while impaired. He previously pleaded guilty to a charge in 2005, and the Broncos stripped him of his captainship.
The Broncos released Williams in the offseason to avoid paying him a $6 million salary in 2013.
The Bears had a clear need at linebacker after the club allowed Urlacher and fellow starter Nick Roach to leave via free agency. The Bears broke off contract negotiations with Urlacher on Wednesday.