He will run the civil engineering businesses within the region, including rail, tunnelling and piling.
Walsh had been with Taylor Woodrow for 17 years since being sponsored by the firm through University. He worked his way up through the ranks to become Vinci UK project director for the last three years.
Walsh brings wide experience in major rail and infrastructure operations like Crossrail and his expertise includes leadership, management and work winning in the London region.
Darren Ramsay, managing director London & South, said: “Peter joins the company at a time of dynamic transition and growth – and his diverse and extensive experience in major projects management and people leadership will be instrumental in helping drive growth in these key sectors.
“Peter will be focused on the safe and sustainable development of these businesses in line with the company’s future growth plans.
“His role will also be key in driving innovation forward, strengthening collaboration with clients, and leading our operations in line with our never harm culture.”
Walsh said: “My immediate focus will be on developing plans for sustainable growth in each of the business sectors while continuing to support our safe, customer-focused, and innovative operations.
“Our industry values increasingly more the responsiveness, solutions and stronger safe working culture which a large direct workforce like Murphy’s can offer.
“People will be key to our success and I am looking forward to working with the women and men that will move Murphy forward.”