Walmart CEO Doug McMillon will retire in January, the retailer announced on Friday.

Walmart’s run as America’s largest retailer appeared to be in jeopardy when Doug McMillon became Walmart’s chief executive 11 years ago.

The world’s biggest retailer said in a regulatory filing on Friday that John Furner would take the reins on February 1, bringing an end to McMillon’s 11-year run as chief, during which time the compan...