Fisher is the current managing director of the Facilities Management, Defence, and Justice (FMDJ) business at Amey.
In her new role, she has replaced Andy Milner, who is leaving the company after a long career including nearly four years in the role of chief executive.
Fisher joined Amey in 2017, having previously held senior operational and leadership positions across sectors including the wider FM market, business services, and highways.
She has worked for companies including Balfour Beatty, Alfred McAlpine, and Allied Healthcare, after a stint as a commissioned officer in the Armed Forces.
Fidel López Soria, chief executive of Ferrovial Services, which owns Amey, said: “Throughout her extraordinary results since joining Amey, Amanda has demonstrated her undoubted ability to assume the position of chief executive.
“I want to wish her all the best for the new challenges she faces.”
The change comes at a key moment for the company, which helps keep services such as utilities, transport, and environmental and waste management running across the country.
Despite gains this year, Amey also formally exited its Birmingham highways PFI contract in September at a cost of £215m, which it will be paying in instalments until 2025.
Earlier this year, the company also reported pre-tax losses of £428m from a £2.3b turnover in 2018.
Fisher said: “I am delighted to have been offered the role to lead Amey through what is both an exciting but demanding time for our industry.
“Recently the business has overcome many challenges, and my focus will be on ensuring we build on this, readying ourselves for the next phrase, delivering what our clients and the communities we serve need.”