Flight BA16, operated by a Boeing 787-9, departed Kingsford Smith Airport at around 2:40pm local time on its regular service to London via Singapore.
Within minutes of leaving the runway, the pilots declared a mayday and requested priority to return, citing concerns over a possible fault on board.
The aircraft circled in the skies southwest of Sydney for more than an hour to burn fuel before making its approach.
Dozens of emergency crews, including fire trucks and paramedics, were positioned along the runway as the Dreamliner touched down safely at 3:56pm. There were no injuries were reported among the travellers or crew.
Sydney Airport confirmed that normal operations continued throughout the incident, with no significant disruption to other flights.
Reports from aviation sources suggest the mayday was connected either to smoke detected on board or to a potential fuel system fault.
Officials have not confirmed the precise cause, but British Airways described the landing as a precautionary measure taken in line with strict safety procedures.
“Our pilots elected to return to Sydney following a technical issue shortly after departure,” the airline said in a statement.
“The aircraft landed safely and our teams are now assisting customers while engineers carry out a full inspection.”
Witnesses at the airport described a heavy emergency services presence as the jet taxied back to the gate. Some travellers waiting for departing flights posted images online showing fire engines alongside the runway.
The flight, one of British Airways’ longest at nearly 17 hours from Singapore to London, was scheduled to continue its journey later in the day. Passengers from the affected service were being rebooked on alternative connections.
