The company said it “aims to increase access to health and fitness activities to a wider demographic to encourage and improve health and wellbeing by providing a low-cost option”.
Kent towns including Strood, Gillingham and Ashford already have their own Gym Group venues and there are more than 240 in the UK.
Councillor Victoria Jones, who represents the area on Tunbridge Wells Borough Council, said: “As the business park takes shape over the next year or so, having a centre for fitness and wellbeing right on its doorstep and accessible to residents in Knights’ Park is a positive development.”
A retail park has been on site for decades but has undergone expansion in recent years, according to Local Democracy Reporting Service.