Chairman Terence Brown says he is sure Trevor will be a great success in his new role - but is, of course, sorry to see him leave.
The Club confirm that Trevor will stand down as a non-executive director as a result of accepting the post that has been created for him by the FA.
Terence says:
"West Ham United's loss will be England's gain and, whilst we are very disappointed to lose Trevor's services and day-to-day involvement, we can also be very proud that Trevor's talents in so many areas of the game have been recognised at national level.
"I am sure Trevor's links with the Club will not be completely severed - and I dare say he will be here from time to time to run the rule over our English talent!
"We wish Trevor every success in his new role and it goes without saying that everyone at West Ham United would like to thank him for his recent contribution to the Club as a director and in two spells as caretaker-manager."
Trevor says:
"I am extremely honoured to have been offered this role by the Football Association although, of course, it was very difficult to relinquish my West Ham United directorship.
"I hope to be able to play a part in moving English football forward, and I will continue to support Alan Pardew and the Hammers in their battle to regain their Premiership status."