Macpherson, who has joined the board as non-executive director, will start his role on 1 January 2024 and will work closely with Manduca, who also chairs St James's Place, to ensure an "orderly handover" of responsibilities.
"I am excited to be joining the board of Templeton Emerging Markets investment trust and look forward to working with the other non-executive directors and the manager," said Macpherson.
"TEMIT has been at the forefront of emerging markets for over 30 years. It has a strong long-term performance which has helped it to grow to be the largest emerging markets investment trust in the UK. Paul Manduca has made an outstanding contribution during his tenure as chairman which, with the help of the board, I hope to build on."
Franklin Templeton appoints CIO for combined global equity business
Manduca added: "I am delighted that Angus has agreed to join the board in October and succeed me as chair in January. He is a first class choice to be the next chair and I wish both him and the company the very best for the future."
Macpherson is currently chair of the Pacific Horizon investment trust and Henderson Diversified Income and a director of Schroder Japan Trust and Hampden & Co. He is also the CEO of Noble and Company, an independent boutique Scottish corporate finance business.
The chair-elect has informed the board of Pacific Horizon that he intends to step down as chair as soon as a suitable successor can be appointed.