The case was dismissed by Superior Court Judge Jessica Silvers due to insufficient evidence and without prejudice.
"I feel I'm being treated fairly now. It was just a terrible accident," Goodman, 70, said outside court.
A dismissal without prejudice means the case could be refiled, but defence attorney Alison Triessl believes it's over.
"We're elated," Triessl said. "This has been a living hell for her. Justice has been served. She did not do this."
Goodman has refereed matches between some of the greatest tennis players in the world.
She had been accused of bludgeoning her 80-year-old husband to death with a coffee cup. She said she was innocent, and her lawyers suggested Alan Goodman died in an accidental fall.
The couple had been married 50 years and had three grown daughters. They lived in the San Fernando Valley area of Los Angeles their entire lives.
Alan Goodman died in April. Authorities initially believed he fell down stairs at home while his wife was away, but they later said it was a homicide after a mortuary reported suspicious injuries on his head.
Authorities then alleged he had been clobbered on the head with a mug, and they began to treat Lois Goodman as a suspect.
But defence lawyers said there was little forensic evidence in the case because of the delay in the investigation. They recently disclosed Lois Goodman had passed polygraph tests supporting her claim of innocence.
She was arrested by Los Angeles police in New York in August as she arrived to be a line judge in the U.S. Open. She made her first court appearance wearing her uniform.
Goodman pleaded not guilty.
After a brief stay in jail, she was released on electronic monitoring and subsequently came to court for pretrial hearings with friends and family present to support her.
"I definitely want to get back to refereeing," Goodman said after the dismissal. "But first I want to call my close friends that supported me and thank them again and again."