Michael Dunn was found guilty of first-degree murder in the killing of 17-year-old Jordan Davis in September, 2012 after an argument over loud music.
The jury took about 5 hours to reach a verdict on Wednesday.
A jury deadlocked in February over whether to convict him of killing Davis.
He was convicted on three counts of attempted murder for shooting at Davis' friends in the car.
Dunn testified at this month's trial as well as his last that he killed Davis in self-defense after the teen threatened him. He also said he thought Davis had a gun, but no weapon was ever found.
At a press conference after the verdict was read, Davis' father, Ron, told reporters, "We must do a better job of loving each other."
More from the Associated Press:
JACKSONVILLE, Fla. (AP) — A Florida man who opened fire on a carload of black teenagers in an argument over their loud "thug" music was convicted Wednesday of first-degree murder.
Prosecutors said Michael Dunn, who is white, was shooting to kill when he fired 10 times into a sport utility vehicle outside a convenience store in November 2012. Jordan Davis, 17, was in the backseat and fatally shot. His three friends in the SUV were not hurt.
Dunn told jurors that he saw Davis, of Marietta, Georgia, roll down the window and flash what he believed to be a gun after the two exchanged words. Dunn said he fired in self-defense.
"I hear '.... white boy' just impolite things are being said," Dunn testified. "I saw the barrel of a gun. I'm petrified. I'm in fear for my life."
Police did not find a gun in the SUV or near the convenience store.
As the court clerk read the jury's verdict, Dunn showed no reaction. Davis' father, Ronald Davis, broke into tears. His mother, Lucia McBath, dropped her head to her chest.
After the verdict, Davis' parents said justice had been done.
"Words cannot express our joy, but also our great sorrow, because with the verdicts of all counts being guilty for Michael Dunn, we know that Jordan has received his justice," McBath said.
At Dunn's first trial in February, he was convicted of three counts of attempted second-degree murder. The jury was hung on the first-degree murder charge, so prosecutors retried him.
Prosecutors didn't seek the death penalty, which means Dunn now faces a mandatory life sentence. He is scheduled to be sentenced Oct. 17. He had already faced at least 60 years for the previous convictions.
Prosecutor John Guy said during opening statements that when Dunn pulled into the parking spot, the music from the SUV was blaring.
"He looked at his girlfriend and said I hate that thug music," Guy said.
Dunn said the problems started when he and his fiancee heard loud bass thumping from an SUV parked next to them after they pulled into a convenience store to buy a bottle of wine. Dunn had just come from his son's wedding.
"I put my window down ... and I said 'Hey, would you mind turning that down please?'" Dunn said.
Testimony from the other teenagers said Dunn was angry when he asked them to turn the music down.
The music was turned off for a short time until Davis started yelling curse words, telling his friends to turn it back up.
Throughout the second trial, prosecutors portrayed Dunn as a cold-blooded killer. Dunn never called 911 after firing into the SUV, and afterward he went back to his hotel, made a drink, ordered pizza, walked his dog and went to sleep.
Even after learning on the news about Davis' death, Dunn drove home to Satellite Beach, Florida, and did not contact authorities until they called him.
Dunn's attorney, Waffa Hanania, did not comment after the verdict.