MacAulay replaces Murray Easton who has retired after 37 years at Balfour.
MacAulay has spent 26 years with Balfour including time as Managing Director of the Southern Regional Civil Engineering business and his most recent role as Managing Director for the Edinburgh Delivery Unit.
He said: “I am delighted to be appointed to my new role for a company I have been dedicated to for most of my professional career.
“I am passionate about building the business and reputation of Balfour Beatty through a first class, customer focused service and delivering great projects that utilise our industry leading engineering expertise.
“I strongly believe the construction industry has a duty and a responsibility to support and enhance the communities within which it operates and to leave a lasting and sustainable legacy when it moves on.”
The Balfour business in Scotland and Ireland has an annual turnover of £400m and operates out of delivery units based in Edinburgh, Paisley, Aberdeen and Dublin.
Dean Banks, Balfour Beatty Managing Director of the UK Construction business, to whom MacAulay will report, said: “I am very pleased to welcome Hector into this role; he has a breadth of invaluable knowledge and experience in the construction industry.
“I am confident Hector will successfully lead and progress our Scottish and Irish business whilst contributing toward the success of the wider Balfour Beatty Group.”