Its half-year results revealed the airport has handled 26.5 million passengers in the six months ending September 30, 2018.
This was only an increase of 100,000 on the previous year, and Gatwick chief executive Stewart Wingate said the limited growth, which equated to 0.5%, was becuase airlines had been building towards full utilisation of slots made available and acquired when Monarch ceased trading.
This also resulted in fewer flights through the airport in the period compared to last year.
However, there was a 21.3% increase in long haul passengers meaning one in six using the airport are now travelling to far-flung destinations
During the same period the airport saw revenue grow by 5.4% to £512.5 million, EBITDA by 5.9% to £325 million, leaving a profit after tax of £139.1million.
Wingate said: “The last six months have seen Gatwick continue to break new ground, while today the airport is serving 46 million annual passengers.
“Gatwick’s ever-growing global connectivity is set to further increase with China Eastern starting a new service to Shanghai in December and Norwegian to Rio in early 2019.
"Growth has been more moderate than in prior years as airlines are currently in the process of gearing up aircraft to be available to serve the capacity created by former Monarch slots.
"We are expecting to see stronger growth once these slots are fully utilised."