Furner started at Walmart in 1993, and currently oversees the most important segment of the company’s business.

John Furner started working for Walmart in 1993. His career with the company has spanned the globe, positioning him to take the top job next year.

John Furner, the Walmart WMT -0.06% lifer who was named Doug McMillon’s successor as chief executive, has been leading the U.S. arm of the retail behemoth for several years, a role he stepped into jus...