The award marked the second consecutive month a Bears player won NFC Defensive Player of the Month. Cornerback Tim Jennings won the award for the month of September.
"He gets better every single year," linebacker Brian Urlacher said. "He's perfect for our defense."
Playing a key role in the team's 4-0 record in October, Tillman intercepted two passes he returned for touchdowns (25-yard INT return at Dallas and 36-yarder at Jacksonville) in addition to limiting Detroit receiver Calvin Johnson to a season-low 34 yards on three catches during the team's Oct. 22 victory over the Lions.
With Tillman leading the way, Chicago's secondary held opponents to an NFL-low passer rating of 61.9, allowing three touchdowns while recording 10 interceptions.
Since last November, Bears players captured three of the last four NFC Defensive Player of the Month awards, with Tillman and Jennings becoming the second duo on the club to win the honor in consecutive months. Defensive end Julius Peppers and linebacker won the award in consecutive months back in 2010.
"No one has a Charles Tillman," Bears coach Lovie Smith said. "There's no one out there like him. When you're on a team and you see a guy like that that has a knack for (getting turnovers), others want to do it. And that's where we are. I'm anxious to see what we'll do this next phase of the season to keep that going and see if our defense can do something special with these takeaways."
In addition to the two interceptions returned for TDs, Tillman has forced three fumbles and recovered another so far this season. Since coming into the league in 2003, Tillman ranks among the NFL's top 10 in interceptions (32), INT return yardage (596), INT returns for TDs (7), forced fumbles (32) and pass breakups (115).
"He's done some things in the NFL that no one's done before and that people will try to mimic in years after," said teammate Lance Briggs.
Tillman ranks No. 3 in franchise history in career interceptions (32).