Jan du Plessis is to succeed Sir Mike Rake as Chairman of BT when he retires on November 1st having been in the job for ten years.
Prior to taking over the role Plessis will join the Board as a Non-Executive Director on June 1st.
He has been Chairman of Rio Tinto since 2009 and also held a number of other senior non-executive roles including a director and Chairman of SABMiller, and as director and Senior Independent Director of Marks & Spencer.
Previously he was Group Finance Director of Richemont and Chairman at British American Tobacco.
Rake said: "While clearly there are continuing challenges, the performance of the company remains on track. This gives me great confidence in its future and I wish Jan every success as he leads BT at this important time."
Plessis added: "This is an important time for the company and I look forward to working with Gavin and his team to help BT continue to support Britain's digital future."