Asda's chief operating officer Richard Baker is moving to Boots as chief executive. Baker, aged 40, will join the high street retailer on September 15.
Recruiting Baker is a coup for Boots, because his background will help it fight increasing competition from supermarkets in the health and beauty sector.
Baker replaces Steve Russell, who retires at the end of this month. Boots chairman John McGrath will be acting chief executive until Baker takes up his appointment.
Baker joined Asda in July 1995 as business unit director. His other posts at the multiple have included deputy trading director and group marketing director. He took his current post in July last year.
Before joining Asda he worked for Mars for nine years, starting as national accounts controller and progressing to head of sales for UK multiples.
Baker said: "I am delighted to be joining Boots. It is one of the most trusted brands in the country."