Greg Foran, 53, currently head of Walmart Asia, will lead the Walmart US division starting August 9, reporting to chief executive Doug McMillon, the company announced.
Foran will replace Bill Simon, who has held the post since June 2010 and "will be transitioning out of the company," Wal-Mart said.
"Greg is one of the most talented retailers I've ever met. His depth of knowledge and global experience will bring a fresh perspective to our business," McMillon said.
The US division, which accounts for about 60 per cent of Wal-Mart's overall revenues, had declining comparable store sales of 0.1 per cent in the most recent quarter, after a 0.4 per cent decline in the previous quarter.