Gatwick has achieved triple certification by the Carbon Trust Standard for cuts in carbon emissions and water use, while also improving waste management.
The airport claimed the highest percentage reduction in absolute CO2 emissions in the transportation sector during a two-year certification period.
Gatwick cut absolute CO2 by 10%, and CO2 per passenger by 20% in 2014-15 against the previous year.
Water use per passenger has been cut by 9.1% compared with 2012-13.
Meanwhile, recycling and reuse rates rose to 49% in 2015, up from 40% the previous year, at the same time as increasing energy recovered from waste from 40% to 47%.
The airport’s chief executive, Stewart Wingate, said: “We are delighted to be one of only a handful of UK companies to achieve the Carbon Trust Standard across three categories of environmental sustainability, but for Gatwick this is just the start.
“Gatwick is already working up a road map detailing how we will become the UK’s leading low carbon airport by 2025.
“We are also examining all other aspects of our footprint – from water through to waste – and will soon announce more exciting plans to reduce our total environmental impact even further.
“These awards are deserved recognition for the whole Gatwick team for their hard work to deliver our ambitious sustainability goals.
“I would like to congratulate them for their efforts and have full confidence that together we will keep going to become one of the greenest airports in the world.”