Simon Calver, 47, will become the new chief executive of childcare retailer Mothercare on April 30, after seven years in charge of the Amazon-owned LoveFilm.
Since 2005, Calver has guided LoveFilm to become Europe's leading DVD and online movie rental firm, now with more than 2m subscribers across the UK, Ireland, Germany, Sweden, Denmark and Norway.
He also oversaw the company during its acquisition by US online retail giant Amazon in early 2011, but leaves as LoveFilm is facing tough competition from Netflix, which recently hailed the success of its UK and Ireland launch.
LoveFilm is also coping with the increasing threat of Sky, as the satellite firm offers movies and TV streaming on its Sky Go multiplatform service, and will soon launch a new online streaming service aimed at attracting pay-TV abstainers, a key part of LoveFilm's market.
Mothercare chairman Alan Parker said that Calver's experience in e-commerce and m-commerce would benefit the firm's UK business, which reported a loss of £81.4m in the six months to November 2011.
"Simon Calver is a highly successful business leader with experience heading multinational consumer facing organisations," said Parker.
"His e-commerce and brand expertise will enable Mothercare to accelerate its development as a multi-channel retailer in the UK and his international perspective will be invaluable to the continued rapid expansion of Mothercare and Early Learning Centre globally."
Calver said: "I am delighted to be joining Mothercare and to have the opportunity to lead this iconic company as we work to consolidate its position as one of the world's leading parenting groups.
"Whilst there are near term challenges ahead, I am committed to the recovery of the UK business and the accelerated growth of these aspirational brands around the world."
There has been no official statement as yet from LoveFilm about Calver's departure, or who will replace him as the firm's chief executive.
