The flight was on its way to London when the incident happened, according to the airline.
An American Airlines flight that took off from Miami Wednesday had to turn right back around after a passenger refused to wear their mask, the airline said.
Flight 38 was heading to London with 129 passengers when the incident happened.
The plane returned to Miami International Airport and was met by authorities, the airline said.
"We thank our crew for their professionalism and apologize to our customers for the inconvenience," American Airlines said in a statement.
The flight was in the air for around an hour and a half before it had to turn around, WFOR-TV reported.
Passengers told the station they were shocked at the situation.
"They wouldn't really say anything, and I don't believe they told the flight attendants anything, either, because they said all they could say was there was an extreme incident with a passenger and they had to turn around," she told the station.
The FAA has reported that as of Tuesday, there have been 151 incidents unruly passengers on flights this year. Ninety-two of those incidents were related to having to wear masks.
