The governments of Jersey and Guernsey have the British Ambassador to Bulgaria to head the new Channels Islands Brussels office.
Steve Williams will become director of European Affairs on 4 April.
He will be the islands' senior representative in Brussels and help develop relationships with key policy makers in Europe.
Mr Williams will also advise the governments of Jersey and Guernsey on European matters.
Senator Terry Le Sueur, Jersey's Chief Minister, said he was pleased to have someone of Mr Williams' "calibre and experience" representing the Channel Islands in Brussels.
Mr Williams said he was looking forward to taking up the position "working with and for the governments, business communities and people of Jersey and Guernsey to promote the Channel Islands' interests in Europe".
The appointment of a deputy director to assist Mr Williams in his new role will be announced shortly.