Rt Revd James Newcome was appointed following an audience with Her Majesty the Queen yesterday.
It means he'll have the responsibility of introducing news bishops to the royal family as well as preaching annually in the Chapel Royal or at the Queen's Chapel in St James's Palace.
Bishop James replaces Rt Revd Christopher Hill, Bishop of Guildford, as Clerk of the Closet.
Speaking about the appointment, he said: "It is an honour to be asked to take on this role and it will be a privilege to support Her Majesty.
"I was surprised and delighted to receive this invitation. I very much look forward to the opportunity it will give me to support my colleagues in the College of Chaplains."
The office of Clerk of the Closet dates from 1437 and includes an annual salary of £7.