Walsh will lead the Law Society until a new permanent CEO is appointed, and he will start in post on 9 December.
Walsh is a “highly experienced” senior executive and consultant, and he is the former interim CEO of the Chartered Institute of Procurement and Supply.
According to the Law Society, he has had a “distinguished career” in infrastructure, including a leading role in the delivery of the 2012 London Olympics.
Stephanie Boyce, Law Society president, said: “Gerry Walsh brings a wealth of experience to the Law Society and, working with our existing team, will help maintain continuity and momentum during an important time for the solicitor’s profession.”
Walsh added: “I’m looking forward to working with the team at the Law Society, helping build on its achievements and making sure it is in the best shape possible for its new permanent chief executive.”