Davidson, currently in charge of legal and company secretarial issues, will also lead on regulatory affairs and sustainable development under the new realignment in responsibilities that followed the company combining its South Africa and Africa divisions into a single region earlier this year.
Davidson’s new job title will be general counsel and corporate affairs director. He will relinquish his role as company secretary; that position will be taken by Stephen Shapiro, currently deputy company secretary and deputy general counsel.
"As a result of this realignment, Catherine May, the group's director of corporate affairs, will leave the group at the end of this month," SABMiller said in a statement.
CEO Alan Clark said: "This further realignment... is consistent with my desire to focus key responsibilities in a smaller and more effective executive group. Combining legal, communications, regulatory affairs and sustainability into one integrated function under John Davidson, reporting directly to me, will serve our business better in a changing legal and regulatory environment."
He added: "I want to thank Catherine for her support over the past two years, in which she has continued to develop critical capabilities to help to grow our business sustainably for the benefit of all of our stakeholders.
"In particular, she has overseen the very successful launch earlier this year of Prosper, our new sustainable development ambition, delivered an excellent leadership engagement programme, and introduced a new corporate identity and digital presence for our business. I am very grateful for her contribution to the group."
Under the current set up, May heads the corporate affairs arm comprising four sub functions: internal and investment engagement, sustainable development, industry affairs, and communications.
The new structure will see the investor relations function sit under chief financial officer Jamie Wilson. Clark said: "Aligning our investor relations activities more closely with our finance team under Jamie Wilson's leadership is a logical development that will further enhance our engagement with financial stakeholders."
Meanwhile, director of corporate finance and development Domenic De Lorenzo will assume additional responsibility for group strategy.
SABMiller owns beer brands including Peroni and Pilsner Urquell.