Speaking at a business conference at Cutlers' Hall, Sheffield, Sharon Kemp, Rotherham Borough Council's chief executive, said it was looking to invite firms to bid to be part of the £150 million redevelopment of the site.
The proposals include a cinema, an 80-bed hotel and a sports and leisure complex in the former Guest and Chrimes building.
Mrs Kemp said: "We are ambitious but realistic about the town centre. We will be going out to tender in the next few weeks for a developer for the Forge Island site."
She also said the council aimed to create 1,000 jobs and build 1,000 homes over the next ten years in Rotherham.
Work to build more than 2,000 homes at Bassingthorpe Farm, near Greasbrough, was also "progressing", she said.