Jack Wills currently has 100 stores in the UK, employing around 1,800 people, with all properties and distribution centres to be transferred to Sports Direct upon completion.
The fashion brand has experienced a difficult year, after reporting losses of £7.5m for the year to 28 January 2018.
It was reported that Edinburgh Woollen Mill owner Philip Day was also interested in acquiring the retailer, as he placed a bid for the company last month.
Suzanne Harlow, chief executive of Jack Wills, said: “For the past year, we have been focussed on improving the Jack Wills proposition and the group’s financial performance.
“Despite significant progress, the challenging trading environment led us to conclude that the company’s long-term future would be best served as part of a larger group and Sports Direct will enable us to do this.”
Will Wright, partner at KPMG and joint administrator, added: “Jack Wills has a strong brand and proud British heritage, so it is pleasing to have been able to secure this agreement with Sports Direct.”
This is the latest acquisition from Ashley’s group, after acquiring Evans Cycles earlier this year, and finalising the takeover of video game retailer Game. Sports Direct has been contacted for comment.