Asda's current president and chief executive, Sean Clarke, will leave his post at the end of the year after just 18 months in the job.
He will be replaced by current deputy chief executive Roger Burnley, who joined Asda a year ago from rival supermarket Sainsbury's.
Asda said Mr Clarke, who used to work for parent company Walmart, would "remain engaged" with the US giant.
Asda said it was always its plan for Mr Burnley to take over as boss of Asda.
Dave Cheesewright, chief executive of Walmart International, said: "Roger was purposefully brought back to Asda to partner with Sean ahead of the transition to Roger taking up the position of CEO.
"He and Sean have worked as a great team and I'm really confident in Roger's ability to continue building upon our returning momentum."