The team announced the dismissal Monday afternoon.
Gettleman was hired as the Panthers' general manager in 2013. During that time, the Panthers won the NFC South three times and compiled a record of 40-23-1.
"After much thought and a long evaluation of our football operations, I have decided to relieve Dave Gettleman of his duties as general manager," Richardson said in a team statement. "I want to thank Dave for the role he played in our success over the past four seasons. While the timing of this decision is not ideal, a change is needed."
Before joining the Panthers, Gettleman was employed for almost 30 years in NFL scouting departments. He has been a part of seven Super Bowl appearances during his decorated tenure. He was with the Buffalo Bills in 1990 and 1991, the Denver Broncos in 1997 and the New York Giants in 200, 2007 and 2011, before joining the Panthers. He was with the Giants for two Super Bowl victories and with the Broncos for their title, along with John Elway and Terrell Davis.
Gettleman, 66, was in a "shaky" place with ownership for some time before the firing, according to NFL Network.
The Panthers start training camp in eight days.