John Caudwell, formerly the boss of Phones 4U, was injured during a raid on his Staffordshire home.
A masked and armed gang broke into Broughton Hall on Monday evening.
Caudwell was hit on the head with an iron bar, which left a one-inch gash. His partner Claire Johnson, 41, and a 22-year-old female member of staff were also assaulted.
Staffordshire Police said: "Both women were assaulted, but not with a weapon, and neither received any injuries."
No firearms were used or seen during the raid.
Caudwell was treated by paramedics at home and had a check-up at Nuffield Hospital.
The gang took jewellery and cash before legging it.
Hat tip to Mobile News for spotting the crime report. ®