Kuechly, a first-round pick from Boston College, led the league with 164 tackles. He began the season on the outside but moved to middle linebacker five games into the season and the Panthers went from 24th in the league in overall defence to 10th.
He earned 28 votes from a nationwide panel of 50 media members who regularly cover the league. That easily outdistanced Seattle LB Bobby Wagner with 11.
Green Bay cornerback Casey Hayward got six votes, while St. Louis CB Janoris Jenkins got three. Tampa Bay LB Lavonte David got the other two votes.
He is the second Panther to win the award; DE Julius Peppers got it in 2002.
Kuechly accepted his award Saturday night at the "2nd Annual NFL Honors" awards show on CBS saluting the NFL's best players, performances and plays from the 2012 season.
Online: http://pro32.ap.org/poll and http://twitter.com/AP_NFL