The investment has seen upgraded facilities including a 22-piece state-of-the-art gymnasium, new dance and fitness studio - with one of the longest ballet barres in the area.
New instructors have been recruited to offer a varied range of fitness classes, with new changing facilities, a new reception and café area, all complementing the centre's existing 30m swimming pool.
Ashville Sports Centre manager, Nigel White, said: “We are delighted to officially unveil this brilliant facility this weekend. We are proud of the new-look centre which sees us moving into the fitness and leisure arena.
"With affordable membership rates and plenty of on-site parking, Ashville is now even more appealing for those wanting to get fit and healthy.
“The taster classes on offer will be a great way for the public to see what a superb addition we now make to Harrogate’s thriving fitness scene.”
On both Saturday and Sunday (December 9 and 10), between 11am and 3pm, non-members will be able to give the facilities a free test-run.
A series of taster classes will be available including spin-a-cise, freestyle kinetics and boxercise in the new fitness studio as well as swimming sessions on offer.
To mark the opening, the centre has also extended its opening times. It is now open week day mornings from 6.15am until 9.30am and week day evenings from 5.45pm until 10pm.
At weekends members can use the facility between 7am and 6pm and in Ashville College School holidays between 6.15am and 10pm.