Source: Sharecast
Harris will replace long-serving current incumbent Tim Jones, who is retiring after 15 years with the FTSE 250 owner of Toby Carvery, All Bar One and O’Neills, among others.
M&B said Jones had played a "pivotal" role in developing the business during his tenure, including strengthening the balance sheet and navigating the pandemic.
He informed the board earlier this year that he planned to step down and take retirement, prompting a "rigorous" recruitment search.
It is not yet been confirmed when Harris, who is currently finance director, food at M&S, will be appointed.
However, M&B said a full handover would likely be achieved by early summer 2026.
Bob Ivell, chair, said: "Emma has demonstrated a strong track record leading finance teams in a wide variety of roles within Asda, Walgreens Boots Alliance and M&S, and we look forward to working with her to capitalise on our strong competitive and financial position, to continue to build value into the future."
Phil Urban, chief executive, added: "Tim has been a valued right-hand man to me through the last years.
"I now look forward to working with Emma, who I believe is a perfect cultural fit for M&B."
Neither Jones nor Harris commented.