Fuccillo has enjoyed spells as manager of Peterborough and Luton Town, and has been chief scout at St James’s Park for eighteen months.
Chairman Huw Jenkins told the club’s official website: “We are absolutely delighted Lil has agreed to join us.
“His appointment is the missing link we’ve been trying to fill for the last few weeks.
“To secure the services of someone with Lil’s knowledge, experience, contacts and network of scouts is a massive plus for the club.”