A statement from Virgin Atlantic confirmed that flight VS27 from Gatwick to Orlando had returned to the airport and been evacuated.
It said: "Due to a technical problem on board the aircraft, the captain decided as a precautionary measure to immediately evacuate the aircraft.
"Our teams at Gatwick are now looking after our passengers and assisting with their immediate requirements.
"The safety and welfare of our crew and passengers is Virgin Atlantic's top priority."
The airline said the Airbus A330-300 aircraft had 13 crew and 299 passengers on board.