Edward Lane Fox, a former captain in the Household Cavalry, has been appointed as Prince Harry's private secretary.
Fox had met the Prince on military duties before working for RLM Finsbury, a financial communications firm, as a senior associate.
Fox will take up his position in June, shortly after the 28-year-old Prince returns from a US tour which is seen as crucial to repairing his reputation after he was photographed naked in Las Vegas, The Telegraph reported.
Prince Harry was involved in the interview process for the appointment, which completes a staff reshuffle that underlines his growing public duties and those of the Duke and Duchess of Cambridge.
He left with the rank of captain in 2006, the year the princes joined the regiment, and became a freelance photographer and journalist before joining Finsbury.
A spokesman for St James's Palace said Fox and Prince Harry had met on occasion and had both been involved with the Burnaby Blue Foundation, a charity which has worked in Lesotho with the Prince's charity, Sentebale.