Lawson will take on the role in November when current Executive Chairman John Dodds will resume the role of Non-Executive Chairman.
Dodds has been running the firm since the departure of former chief executive Tom Haughey.
Severfield has suffered a turbulent few years running-up a pre-tax loss of £29m in the 15 months to March 2013.
The bulk of the loss was down to its Cheesegrater office contract in London, but its woes were also compounded by several other problem jobs.
A round of restructuring and refinancing costs incurred from a £45m share placing earlier this year have also hit the firm.
Dodds has been hunting for a new chief exec for months and returned to his old stamping ground at Kier where he was in charge from 2003 to 2010.
Lawson worked at Kier for 13 years – latterly as executive director of the property and development businesses.
He was previously Director of Kier Regional, the Group’s regional construction business.
Prior to joining Kier Regional, Lawson was Managing Director of Kier Investments which he joined in 2000 following a successful career at Bickerton Group where he was Managing Director.
He left the firm in June ahead of Kier’s acquisition of May Gurney.
Dodds said: “I am delighted to welcome Ian to the Group. He has a wide range of experience from 35 years in the construction industry.
“I have worked with Ian over many years and believe he brings the right mix of skills and experience to lead the Group for the next phase of its growth and development.”