The first phase includes roof repairs to the Pavilion Arts Centre and office area, as well as the roofs above the retail units and cafe seating areas.
Phase two will concentrate on the conservatory roof sections and upgrades to public toilet facilities.
Damien Greenhalgh, deputy leader of the council, said: “The Pavilion Gardens is one of our most valued assets in the High Peak and one of our most cherished attractions for residents and visitors alike.
“This important investment is about protecting its historic character while ensuring it continues to offer a fantastic experience for generations to come.
“While the first phase of these essential works is under way, the Gardens remain very much open, so we encourage everyone to keep visiting, enjoy the events, shops and cafes, and love all this iconic destination has to offer.”