Properties include a four bedroom penthouse on the 14th floor which sold for more than the £1.4 million price tag after going to sealed bids.
Demand for apartments has been intense and 82% are now sold on the site of the former hotel on Fulwood Road, Broomhill.
Hallam Towers has 103 apartments and penthouses, which are being marketed by estate agent Redbrik and are due to be completed in October 2022. The one, two and three-bedroom apartments and penthouses have prices ranging from £215,000 to £1.4 million.
Director Peter Lee said: “The total sales make it one of the most expensive developments in Sheffield. ”
He added more than one person was prepared to more than £1.4 million to get the top floor penthouse.
Mr Lee said: "The real draw for the people of Sheffield was that Hallam Towers was a building before this development so getting planning permission was relatively easy.
"There won’t be another building like this because if you look across S10 there are four or five storey buildings nestled in the trees, you can’t go higher.
"Hallam Towers is unique and people wanted to take advantage of it.”
He added the top floor penthouse covers 2,600 sq ft and has a 600ft roof terrace. This penthouse started out at 1500 sq ft but was expanded because buyers wanted more space.
"It will be an absolutely stunning and amazing duplex,” added Mr Lee. "People were fighting over it.” Two smaller penthouses have also been sold, one for £800,000 and the other for an undisclosed price.
Jen Beal, Redbrik’s land and new homes manager, said: “This is a great project and we are excited to be involved in the marketing and creative aspiration of this luxury development.”
Mr Lee added: “We have been dealing with the concept side for four years so it will be amazing to hand over the keys when we open the doors and our buyers walk into something complete.”
Residents will have access to a swimming pool, gym, on-site concierge and electric car charging points. For more information about Hallam Towers, click here.