McGregor, who starred in the Ultimate Fighter Championship promotion, was accused of stealing and smashing a fan's cellphone outside a Miami Beach hotel in March.
McGregor, 30, was charged with strong-armed robbery and criminal mischief after the March 11 incident, WPLG reported.
The victim, Ahmed Abdirzik, dropped a civil suit against McGregor, ESPN reported. He had been seeking more than $15,000 in damages.
Prosecutor Khalil Madani, of the State Attorney's Office in Miami-Dade County, said Monday the charges were dropped because Abdirzik stopped cooperating with authorities, the Herald reported.
“The victim of the crime does not wish to return to the United States and prosecute this case,” Madani said in court.
McGregor did not appear in court for Monday's brief hearing, according to the Herald.
He was in South Florida in March with his girlfriend and son to celebrate his mother's birthday, WPLG reported.