Rivera, 52, took over as head coach the Panthers in 2011 and the team has improved its record each season, going 12-4 in the 2013 regular season. Carolina was defeated by the San Francisco 49ers in the NFC Divisional round of the playoffs.
He is the first Carolina coach to win the honor from the Professional Football Writers of America since Dom Capers won it in 1995 and '96. Rivera was selected the PFWA Assistant Coach of the Year in 2005 when he was on the staff of the Chicago Bears.
The PFWA also announced Thursday that John Dorsey, in his first year as general manager of the Kansas City Chiefs, was its NFL Executive of the Year. The Chiefs were an NFL-worst 2-14 in 2012 but went 11-5 and reached the playoffs in 2013.
Notable deaths of 2014 [PHOTOS]
Michael Sam cut from the Dallas Cowboys