On 28 - 29 May visitors will be welcomed by circus performers, artists, musicians and sports coaches in celebration of the park's opening.
The public was granted use of the park by WL Wharton in 1858 and it was the site of the first Durham Miners’ Gala in 1871. The park includes a play area, gardens, walks and other recreational activities.
Changes include the restoration of a popular miniature car track and the creation of a new heritage centre, playgrounds and fitness areas.
Improvements to the park’s amphitheatre, miniature car track, footpaths, signs and main entrances were also carried out, and new jobs including a park manager were created as well as apprenticeship opportunities.
Neil Foster, Durham County Council's cabinet member for economic regeneration, arts and culture, said: "Wharton Park is one of Durham's hidden gems and it is fantastic to see it rejuvenated and ready to welcome visitors to the city.
"For locals the park provides important green space and recreational opportunities, while with improved access and exciting new additions like the heritage centre, I hope it will be another great string in what is already a magnificent tourism bow, encouraging more and more people to come to the county."
The restoration was carried out by the council, which put in £600,000 on top of £2.4m in funding from the Heritage Lottery Fund and Big Lottery Fund.