Zimmerman had filed the suit in December 2012 alleging NBC portrayed him as racist in a series of news reports about Martin’s death in February 2012.
Circuit Judge Debra S. Nelson made the ruling Monday. She had written that Zimmerman was a “public figure” and he had to prove “actual malice.”
“NBC News is gratified by the court’s dismissal of this lawsuit, which we have always believed to be without merit,” the network said in a statement.
Nelson had placed Zimmerman’s suit on hold pending his criminal trial. He was acquitted in 2013 of second-degree murder and manslaughter in Martin’s shooting at a gated community in Florida.
Zimmerman had accused NBC News of defaming him by broadcasting edited clips of a 911 call he made. Those clips made it appear as if Zimmerman volunteered that the teenager was black and had been racially profiled when Zimmmerman had actually said “he looks black” in response to 911 dispatcher asking, “Is he black, white or Hispanic?”