Fox will join the group on September 4 as chief executive-designate, replacing Alan Giles who will step down as a director at the group's AGM on September 28.
Fox revealed he was leaving Kesa last week. As chief operating officer he was responsible for Comet in the UK and several of Kesa's subsidiaries in continental Europe, including BCC, Vanden Borre and Datart. He was also responsible for the electricals group's e-commerce developments. Fox was managing director of Comet before being promoted to chief operating officer in February.
Simon Fox said: 'We all know that these are highly competitive markets, but I firmly believe the stellar attributes which are in the DNA of the brands and operating culture will enable the group's businesses to successfully differentiate themselves through a variety of complementary retail channels.'
HMV group non-executive chairman Carl Symon said: 'We had an excellent list of talented candidates to consider and Simon's background in highly competitive retail markets, his international experience and his expertise in developing leading online brands stood out.'
Seymour Pierce analyst Richard Ratner said: 'We expect Fox to bring his experience of developing the Comet online brand to his new role as HMV has been a slow starter in an overcrowded online market.'
Prior to joining Comet, Fox founded and managed office supplies specialist Office World and was chief executive of stationers Sandhurst, which was acquired by WHSmith.