McAdam has held the role for 13 years and also served as chief executive from November 1992 to March 2000. He has been hailed as the man responsible for turning around the retailer's fortunes in the early 1990s following the departure of unwisely candid boss Gerald Ratner.
Signet also announced the promotion of UK chief executive Rob Anderson to the role of executive director. Anderson joined the group as UK chief operating officer in 2000. Previously, he was at Marks & Spencer for 19 years, rising to the position of business unit director.
The retailer made the announcement at the same time as publishing its results for the year to January 29, where it revealed a group pre-tax profit of£210 million.