The 12 existing staff will continue to work at the store, and the shoe shop in Orchard Square shopping centre has been given a fresh new look and feel.
The business has also purchased a second Clarks franchise in Wilmslow, Cheshire, with a further five permanent staff, bringing the company's total number of Clarks franchise stores to seven.
Established in 1978, Tonks Shoes, was launched by Jeffrey and Elizabeth Tonks as an independent shoe retailer selling men's, women's and children's shoes.
Michael Tonks, their son, took over the business in 1982, opening franchises under the Tonks Shoes brand, until the firm became an official Clarks franchisee in 2000, changing its existing stores to be under the Clarks brand.
Now in its third generation, Matthew Tonks is managing director of the Leigh-headquartered business, overseeing its seven franchises across the North West and Yorkshire.
The two recent acquisitions bring the company's total number of staff to close to 100 and will contribute to an annual turnover of over £4m.
With the continued support from NatWest, Tonks Shoes Ltd will work closely with Clarks to explore other opportunities to expand their franchise portfolio.
Matthew Tonks said: "By adding two more stores to our portfolio, we have supported Clarks' high street presence and kept experienced staff in the process. The backing from NatWest has enabled us to take ownership of this valued Sheffield store, continuing to bring the products from this established and iconic brand to the town."
Ruth Kirby, relationship manager at NatWest, said: "Tonks Shoes is passionate about supporting high street stores in towns across the North of England. We look forward to supporting the business in the future as Matthew and the team look to expand the firm's portfolio further."
