Williams has headed the Thames Gateway regeneration agency for the past six years. During that time it has grown from a small initiative in east London to a large agency with a national reputation.
In his new role as chief executive of the Camborne, Pool and Redruth Urban Regeneration Company, Williams will have the job of masterminding its investment plan.
The company's ultimate aim is to regenerate 150 ha of land, making it one of the largest urban renewal projects in the country.
Williams said: "There's a bit of a renaissance going on in Cornwall.
I want to use my experience in a hands-on way for the Camborne area, which has a great heritage but has to reinvent itself."
He added that he felt a kinship with the area – his home town is Pontypridd in south Wales, which also has a mining background. He said that he was excited by the challenge of reinventing the area.
It has been suggested that the regeneration will be based around a replica of an 18th-century mining village, with tours of disused mining shafts and listed buildings in Pool.
Camborne, Pool and Redruth make up the largest conurbation in Cornwall, with a population of 45,000 over a five-mile urban corridor of brownfield land.
Last year the company secured £750,000 of Objective One funding from the European Union to run the business over the next three years.
Cornwall and Kerrier councils, which are key partners and match funders, both provided £375,000, and the South West Regional Development Agency provided £750,000.
English Partnerships, the Prince's Foundation and private sector investors will also provide funding. Nigel Smith, the acting chief executive who set up the company in September last year, will hand over to Williams in June.
Smith has so far instigated compulsory purchase orders for 25 sites on 30 ha of derelict brownfield land in south Pool; commissioned a study for a £10m fitness and extreme sports centre in Pool; and driven forward a £5m project to create 50,000 ft2 of purpose-built office space for use by small and medium-sized enterprises.