Gatwick is warning passengers of significant disruption to rail services serving the airport as strikes start tonight.
On December 13, 14 and 16, there will be no Southern trains and reduced Gatwick Express services.
More than a third of Gatwick passengers arrive by train.
"Please plan your journey in advance and allow plenty of extra time to get to the airport. You may want to consider alternatives methods of transport," the airport said.
There will be no Southern services and although Thameslink trains, which run on the same line, are not expected to be affected by the strike, they will be extremely busy.
There will be no Gatwick Express services from Gatwick to Brighton.
Thameslink, Southern and Gatwick Express will be accepting each other’s tickets during the strike.
The strikes are part of a long-running dispute with management and unions over plans to run trains with only drivers on board.
This is the first time Southern drivers have walked out. So far the industrial action has only been by RMT guards.
Southern is today making a last ditch attempt to stop the action in the Court of Appeal.
