The victim died in the early hours of last Friday and is understood to have been acting as a slinger during a tower crane lift of steelwork.
A message to staff seen by the Enquirer from client Network Rail chief executive Andrew Haines said: “We have learnt of the dreadful news that in the early hours of Friday morning a construction colleague, working for Kilnbridge on the Gatwick Airport station construction project, sadly died following an incident on site.
“Kilnbridge are a subcontractor to Costain who are in charge of the site at Gatwick as the principal contractor.
“Any loss of life in our railway family is deeply painful and I know our thoughts are with all those affected.
“We will do all we can to support the man’s family and to support colleagues based on site.”
An investigation into the incident is being conducted by the British Transport Police and the HSE.