The six-person jury, comprised of five men and one woman, signalled that they had reached a verdict today after 5.5 hours of deliberation.
He could be given 30 years in prison when sentenced on April 30.
The judge denied defense attorney Roy Black's request for Goodman to be released on bail and Goodman was taken into custody.
Goodman's Bentley slammed into Scott Wilson's Hyundai and sent it into a nearby canal in Wellington, Fla., in February 2010. Wilson, a 23-year-old engineering graduate, was still strapped into the driver's seat and drowned.
Wilson's mother was tearful as she left the courtroom. "I know that it took a lot for them come up with a conclusion and justice has been served. I'm always going to miss my son," Lili Wilson said. "I will always share his memories. And now, coming from me and the rest of the family and his friends, it's time for the healing process to begin."
Scott Wilson's father William Wilson exited the courtoom and his attorney made a statement on his behalf.
"Mr. Wilson lost not only his son, but his best friend, an engineering colleague and a Florida Gators fan," the attorney said.
The attorney said his client is "still inflicted with harrowing pain, grief and sorrow that cannot be shaken," two years after his son's death.
The multi-millionaire founder of the International Polo Club Palm Beach claims his $200,000 car malfunctioned and lurched forward. He has also denied being drunk at the time of the crash that killed Wilson, although other testimony has contradicted him and his blood alcohol level was more than twice the legal limit three hours after the crash.
"I think that justice was served. I think [jurors] were very careful," prosecutor Ellen Roberts said at a news conference. "They went over a lot of evidence and I think they probably returned the only verdict they could."
Roberts said she would not know what sentence she planned to recommend to the judge until she spoke with the Wilson family.
Defense attorney Roy Black left stopped briefly as he came out of the courtroom and said, "I have no comment. I have nothing further to say at this time." He later issued a statement saying that Goodman will appeal the conviction.
"It is our belief that multiple errors were committed during and before the trial that, in effect, denied our client's ability to get a fair trial. We intend to file an appeal so that our client can receive the just and fair proceeding to which he is entitled by law," Black said.
Goodman's mother was sobbing as she left the courthouse.
When attorneys from both sides had their last chance to appeal to jurors in Thursday's closing arguments, they battled about the events of the night of the accident, focusing on how much Goodman had to drink.
"The defendant was impaired, the defendant was speeding, the defendant ran a stop sign, the defendant probably unintentionally had too much to drink that night," prosecutor Sherri Collins said in her closing arguments. "And when the crash happened, did he go around and look at the front of the car to see what he hit or to the canal that was three feet away? No, he headed south."
"He didn't do any of the things that are required by law and, ladies and gentlemen, there is no excuse for that," she said.
When Goodman, 48, took the stand, he denied drinking powerful cocktails known as Irish car bombs and mind erasers, which defense attorney Roy Black reiterated in his closing arguments.
"At the White Horse Tavern, there are five eyewitnesses. The eyewitnesses unanimously say John Goodman had one drink. Unanimously," Black said.
The defense argued that Goodman's blood alcohol level was high because after the accident, he stumbled to a nearby barn where he tried to call for help and drank from a bottle of liquor he found there to ease the pain from a broken wrist, fractured chest and back injuries.
"There's no doubt this case is a tragedy, that a young man lost his life," Black said. "This is a sad thing. We all recognize that, but we're not here to compound that tragedy with another one. This is a horrible accident, but this is not a crime."
Goodman has already settled a civil suit over the crash after adopting his 42-year-old girlfriend to help protect his estate.