He starts at Lavendon, parent company of Nationwide Platforms, on 1 October.
Mr Kenny, aged 56 and a qualified accountant, has been at Carillion since 2002, serving on the main board as an executive director since 2006. He was group managing director of Carillion Business Services, the facilities management arm that has revenues of £1.2bn and 15,000 employees.
Before joining Carillion, he was managing director of Johnson Controls IFM UK ("Johnson Controls"), and before that a vice president of Sulzer Infra.
In his earlier career, Mr Kenny held several general and financial management roles in the UK, Asia, Middle East and Scandinavia with Mowlem.
Lavendon chairman John Standen said: "We are delighted that Don is joining Lavendon as chief executive. He brings with him a wealth of experience of improving operating performance and growing businesses successfully both in the UK and internationally, together with a deep understanding of our industrial end markets. He is the ideal candidate to lead the group through the next phase of its development and I am confident that he will deliver significant shareholder value."
Mr Kenny said: "I am delighted to be joining Lavendon at this stage in its development, and look forward to working with the board and the executive management team to further the group's potential, leveraging its strong market positions and improving its return on capital employed."