He replaces Doug Mallory who was fired on Jan. 10.
Knorr spent the previous three seasons as the defensive coordinator at Wake Forest. Prior to that, he spent several seasons as an assistant at both the Air Force Academy and Ohio University. He was also the head coach at Ohio from 2001-04.
"We want to welcome Brian and his family to the Hoosier Nation," Wilson said. "Brian is a strong addition to our coaching staff. He brings tremendous experience and a solid background having coached on both sides of the ball, as a defensive coordinator and as an FBS head coach. We are excited to work together to take a positive step in building a winning program that our players and fans deserve."
Many of the following details were supplied by Indiana's media relations department in a release Monday morning announcing the hire.
At Wake Forest, Knorr worked with the outside linebackers in 2013 after he coached the inside linebackers in 2011 and 2012. The Demon Deacons allowed 24.1 points (38th nationally), 143.2 rushing yards (34th), 223.0 passing yards and 366.2 total yards (32nd) per game last season.
"Having known Coach Wilson for the past 20 years, his personality and the type of team he fields, I am excited to join his staff," Knorr said. "There is a buzz about the direction IU Football is headed in and I look forward to bringing some of the toughness and aggressiveness that I know Coach Wilson wants to implement on the defensive side of the ball."
In 2012, WFU forced 23 turnovers and ranked second in the ACC with 12 forced fumbles. During conference play, Wake Forest ranked in the top half of the conference in eight of the 12 major defensive categories. Inside linebacker Mike Olson finished second on the team with 78 tackles, while fellow inside linebacker Riley Haynes ended the campaign fourth with 60 stops.
He served as co-coordinator in 2011 and implemented a 3-4 scheme that led to an improvement in every defensive category. Four members of the defense received invites to NFL camps and two were drafted - Kyle Wilber in the fourth round by the Dallas Cowboys and Josh Bush in the sixth round by the New York Jets.
Knorr arrived at Wake Forest after three years at Air Force. He tutored the strong safeties and outside linebackers in 2005 and 2006, and the inside linebackers in 2007. His 2007 linebacking corps featured two all-conference selections. The defense helped the Falcons to one of the best turnarounds in Division I FBS football that same season.
A 1986 graduate of the Air Force Academy with a degree in management, Knorr lettered three years at quarterback. Air Force won 30 games, the top three-year span in school history.
Knorr served in the Air Force at Wright-Patterson Air Force Base in Dayton, Ohio, after he graduated. He earned his master's in business administration from the University of Dayton in 1991.
In 1992, he returned to the Academy as a captain and member of the coaching staff. Knorr was the assistant offensive line coach, junior varsity head coach and administrative assistant to the head coach.
He left the Academy in 1995 to become the inside linebackers coach at Ohio and was elevated to defensive coordinator in 1999. The 2000 Bobcats held all of their opponents to less than 30 points in every contest, one of just five teams in the nation to accomplish this feat.
Ohio's defense ranked in the top five in the Mid-American Conference in scoring, rushing and total defense every year during his time as coordinator. Five of Knorr's players earned all-conference accolades.
Following the 2000 season, Knorr became the first Air Force Academy graduate to be named a head football coach at the Division I level. In addition to his head coaching duties, he coordinated the Bobcats special teams and a punt team that led the NCAA in 2001.
Upon his arrival at Wake Forest, Knorr spent three seasons as the program's wide receivers coach. Junior Marshall Williams led his 2009 receivers and finished third in the ACC in receiving yards per game and fourth in receptions per game. Redshirt freshman Chris Givens topped the nation's freshmen with eight touchdown receptions. Devon Brown paced the team with 61 catches and totaled seven TDs.
D.J. Boldin, who signed a free agent contract with the Detroit Lions, led the ACC with 81 receptions in 2008. It marked the second-highest single-season mark by a Demon Deacons wide receiver.
Knorr was born on Dec. 20, 1963, and is a native of Shawnee Mission, Kan. He and his wife Julie, an Indiana University graduate and a native of Fort Wayne, Ind., have a daughter, Katie, and twins, Reagan and Brett.