The Bears also signed tight end Jeron Mastrud, a four-year veteran who started 12 games with the Oakland Raiders last season.
Wilson had been regarded as one of the league's premier safeties during his 12-year tenure with the Arizona Cardinals from 2001-12, earning All-Pro honors three times in addition to his five Pro Bowl citations. The 34-year-old joined the New England Patriots last offseason, but spent the entire 2013 campaign on injured reserve after tearing his Achilles tendon in August.
The Patriots released Wilson, one of only 13 players to record 20 or more sacks and interceptions over the course of their career, in April.
Wilson made 14 starts for the Cardinals in 2012, compiling 54 tackles, three sacks and one interception.
Mastrud, who spent three seasons with Miami prior to landing with the Raiders in 2013, has primarily served as a blocking specialist, as his six receptions in 2013 were a career high.