He replaces Kate Bowyer, who left in April after taking the helm from Matt Crompton around 18 months ago.
Mayall joined Muse in 2006 to progress through the business to run the North West territory in 2019.
He was responsible for delivering major growth across this region, with a wide range of long-term, area-wide programmes of place-changing regeneration.
He is also a director of The English Cities Fund, a national regeneration partnership between Muse, Homes England and Legal and General.
Mayall, said: “Our business is all about creating vibrant places in partnership, that build brighter futures for communities up and down the country.
“I’m excited for what the future holds at Muse and I look forward to working with colleagues and partners to deliver more long-term projects that transform our towns and cities and provide opportunities for all to thrive.”