ASOS (LON:ASC) chief executive and founder Nick Robertson is standing down after 15 years in the role.
Robertson, who will stay with the company as a non-executive director, will be replaced by chief operating officer Nick Beighton immediately.
In April, ASOS announced the appointment of Helen Ashton as finance chief, succeeding Beighton who doubled up with the finance brief. Ashton started with the company on Tuesday.
Chairman Brian McBride said Robertson had built a start-up into a world class company.
"We are all delighted Nick will continue to contribute to the company he started," he said. "We are fortunate to have such an able successor for the CEO role in Nick Beighton. Nick has unique experience of the company built over six years, equipping him to drive ASOS along its growth trajectory to become the world's leading online fashion retailer for 20 - somethings."